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Direct Final Rule Amending the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and the Amending of Emission Standard Provisions for Gaseous Fueled Vehicles and Engines


[Federal Register: September 5, 1997 (Volume 62, Number 172)]
[Rules and Regulations]
[Page 47113-47136]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05se97-22]

[[Page 47113]]

_______________________________________________________________________

Part II

Environmental Protection Agency

_______________________________________________________________________

40 CFR Parts 9 and 86

Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and
Trucks, and Emission Standard Provisions for Gaseous Fueled Vehicles,
and Engines, Amendments; Final Rule

[[Page 47114]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 9 and 86

[FRL-5881-3]


Direct Final Rule Amending the Test Procedures for Heavy-Duty
Engines, and Light-Duty Vehicles and Trucks and the Amending of
Emission Standard Provisions for Gaseous Fueled Vehicles and Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: This action promulgates amendments to several sections of the
heavy-duty engine test procedure regulations in 40 CFR part 86. These
changes are needed in order to accommodate the use of new testing
equipment, to provide greater flexibility in the type of testing
equipment used and to ensure uniform calibration and use of the testing
equipment. The amendments will ensure the continued validity of testing
results and ensure that heavy-duty engines are being exercised
appropriately over the test procedures. This action also makes limited
changes to the light-duty vehicle and truck test procedure regulations
and the gaseous fuel emission standards in 40 CFR part 86. Because
changes are limited to technical issues, all of which have been
coordinated with industry, EPA expects no adverse comments.

DATES: This rule will be effective January 5, 1998 unless notice is
received by October 6, 1997 that adverse or critical comments will be
submitted on a specific element of this rule. If such comments are
received, then EPA will publish a subsequent document in the Federal
Register withdrawing any regulation for which adverse or critical
comments were made.
    The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 5, 1998.

ADDRESSES: Interested parties may submit written comments in response
to this notice (in duplicate, if possible) to Public Docket A-96-07 at
Air Docket Section, U.S. Environmental Protection Agency, First Floor,
Waterside Mall, Room M-1500, 401 M Street SW, Washington DC 20460. A
copy of the comments should also be sent to the contact person listed
below.

FOR FURTHER INFORMATION CONTACT: Mr. Jaime Pagan, U.S. Environmental
Protection Agency, Engine Programs and Compliance Division, 2565
Plymouth Rd., Ann Arbor, MI 48105. Telephone: (313) 668-4574, fax:
(313) 741-7816.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. List of Changes to Test Procedures
III. Environmental and Economic Impacts
IV. Public Participation
V. Statutory Authority
VI. Administrative Designation and Regulatory Analysis
VII. Compliance with Regulatory Flexibility Act
VIII. Unfunded Mandates
IX. Paperwork Reduction Act
X. Submission to Congress and the General Accounting Office
XI. Copies of Rulemaking Documents

I. Introduction

    EPA's Smoke Exhaust and Gaseous and Particulate Exhaust Test
Procedures for certification and Selective Enforcement Audit (SEA)
provide a consistent method for testing and obtaining emissions data
from heavy-duty engines. This action promulgates amendments to the test
procedures in order to accommodate the use of new testing equipment and
clarify certain issues that have been identified since these procedures
were first published.
    Over the last few years, EPA and the Engine Manufacturers
Association (EMA) have worked together to identify the issues that
needed revision or clarification. During these interactions,
suggestions were made involving specific changes to the test
procedures. In general, the technical amendments included in this
action fall into two categories. First, many of the amendments are
simply clarifications that will help remove any potential ambiguities
or inconsistencies. Second, another group of amendments take into
account testing equipment and/or engine technology that was not as
widely used when the rule was first written.
    The changes to the Smoke Exhaust Test Procedure include
clarifications regarding the operation of the dynamometer,
accommodation of additional test equipment and more details on meter
light sources to be used. The test procedures for SEA contain a new
requirement that asks manufacturers to decide, before the initial cold
cycle, whether they will measure background particulate matter (PM) or
not. Promulgated amendments to the Gaseous and Particulate Test
Procedures cover the calibration requirements of gas analyzers, the use
of accessory loads, conditions for use of charge air cooling devices
and the permitted point deletions from regression analysis.
    Lastly, three minor changes to the Gaseous Fueled Vehicle Rule,
established in a September 21, 1994 notice (59 FR 48472), are made. The
regulatory text of that rule contained several minor errors and areas
where the applicability of various standards to gaseous-fueled vehicles
was not clear in the regulations, although all of the applicability
issues were discussed in the preamble. The following section presents a
more detailed overview of the specific amendments that EPA is
promulgating in this action.

II. List of Changes to Test Procedures

    1. Changes and clarifications regarding dynamometer control
throughout the operation cycle for smoke emission tests (Sec. 86.884-
7(a) and Sec. 86.884-13(b)(6)). These changes respond to the need to
better define the acceleration mode in the smoke test cycle. The
amendments to the regulatory language make the speed and acceleration
requirements more specific. In addition, it is clarified that during
the last 10 seconds of the lugging mode the average engine speed and
the average observed power shall be maintained within their specified
values. Furthermore, the regulations are revised to state that within
five seconds of the completion of the lugging mode, the dynamometer and
engine controls shall be returned to idle position. These
specifications are needed to ensure uniformity in how the procedures
are followed.
    2. Allow the use of newer in-line smokemeters and accommodate
multistack engines to the smoke exhaust test procedure (Sec. 86.884-
8(c) and Sec. 86.884-14). In-line smokemeters, which were not available
when the original rule was written, are now taken into account in the
test procedure. The purpose of this addition is to provide engine
manufacturers the flexibility of using this type of equipment. The use
of in-line smokemeters is acceptable since it does not affect test
results. Also, specifications for the distance between the smokemeter
and the exhaust manifold, turbocharger outlet, aftertreatment device or
crossover junction (whichever is farthest downstream), are now included
in the regulations. Such distance specifications are needed to ensure a
uniform procedure and repeatable test results.
    3. Clarify the specifications for the type of light sources to be
used during smoke testing (Sec. 86.884-9 (b)(2) and (c)). These
clarifications specify the color temperature range and spectral peak
for

[[Page 47115]]

smokemeter light sources. It is also specified that light detectors
shall be a photocell or a photodiode. In addition, it is now specified
that the distance from the optical centerline of the smokemeter to the
exhaust pipe outlet is 10.25 inches. The new language adds
specificity by providing specific ranges for these parameters and adds
flexibility by allowing the use of more current smokemeter technology.
    4. Semantic clarification for the smoke test: Curb Idle rpm versus
Idle rpm (Sec. 86.884-7(a)(4) and Sec. 86.884-10(a)(8)). The word
``Curb'' was eliminated from the term ``Curb Idle rpm'' in the smoke
test procedure. When running a smoke test on an engine with Curb Idle
Transmission Torque (CITT), it is very difficult to maintain the
desired idle speed without having to adjust the controls. The change in
the regulatory language simply allows to operate the engine at free
idle speed and does not affect test results.
    5. New calculations are provided to support the use of in-line
smokemeters (Sec. 86.884-14(a)). EPA provides an equation to determine
the standard half-second percent opacity, if the opacity is being
measured using a smokemeter with a different optical path length than
the one specified in Sec. 86.884-8. This calculation will help support
the use of current in-line smokemeters.
    6. Selective Enforcement Auditing Test Procedures: Require that
manufacturers decide, before the start of the cold cycle, whether they
will measure background particulate matter (PM). The test shall be
voided if the manufacturer fails to measure background PM after
initially saying it would (Sec. 86.1008-90(a), Sec. 86.1008-96(a),
Sec. 86.1008-2001(a) and Sec. 86.1111-87(a)). The CFR
(Sec. 86.1310(b)(1)(iv)(C)) states that the primary dilution air may be
sampled to determine background PM levels. Since this measurement is
not required, a valid test may be run without sampling for background
particulate. Background particulate can make a significant contribution
to the total particulate collected on the sample filter, especially at
emission levels of 0.10 g/bhp-hr and below. As a result, most
manufacturers choose to measure background particulate.
    During Selective Enforcement Audit (SEA) testing, manufacturers
will occasionally have problems measuring background particulate.
Improper handling of the background filters is the usual cause of these
problems. Manufacturers typically want to weigh the sample filters
before deciding whether or not to void the test. If the engine passes
based on the sample filter weights, the manufacturer will not void the
test since including background emissions will only lower an already
passing particulate value. However, if the engine fails based solely on
the sample filter weights, the manufacturer will want to void the test
since the engine may pass if background correction is included.
    Although it is certain that an engine that passes without
background correction will pass with background correction, it is
uncertain if an unmeasured background correction will lower the
particulate level of a failing engine enough to pass. An engine with
failing sample filter weights may pass when retested solely as the
result of test-to-test variability, lowering its emission level.
    Therefore EPA will now require that manufacturers decide, before
the start of the cold cycle, whether they will measure background PM.
The test shall be voided if the manufacturer fails to measure
background PM after initially saying it would.
    7. Clarify the procedure for sampling background particulate
(Sec. 86.1310-90(b)(1)(iv)(C)). The new language adds specificity to
the exhaust gas sampling method by stipulating that the primary
dilution air shall be sampled at the inlet to the primary dilution
tunnel, if unfiltered, or downstream of any primary dilution air
conditioning devices that are used.
    8. Clarify the hydrocarbon (HC) probe location and line temperature
requirements and introduce a new approach for demonstrating the
temperature profile of heated lines (Sec. 86.1310-90(b)(3)). This
clarification will provide more uniformity to the test procedures by
requiring specific probe locations and line temperature requirements.
The revisions to the regulations require that the temperature
requirements of the hydrocarbon (HC) sample line shall be met over its
entire length and not just at the measurement points. Since the gas
temperature can not instantly be brought up to the required
temperature, the length of the sample probe is defined as the length at
which the gas temperature must meet specifications.
    9. Require that all particulate matter (PM) filters (sample,
reference and background) are to be handled in pairs during all
weighing (Sec. 86.1310-90(b)(7), Sec. 86.1312-88(a) (3) & (4), and
Sec. 86.1337). This measure will help reduce error and ensure the
uniform use of all filter samples. More accurate measurements can be
obtained by weighing the filters in pairs.
    10. Recommend that PM filter loading be maximized consistent with
other temperature requirements and the requirement to avoid moisture
condensation (Sec. 86.1310-90(b)(7)(iv)). The new language will ensure
that PM measurements are accurate by having a filter loading that is
consistent with temperature and moisture requirements. Furthermore, EPA
recommends that the filter pair loading be proportional to the engine's
emission level. For example, a filter pair loading of 1 mg is typically
proportional to a 0.1 g/bhp-hr PM emission level. This change
eliminates the previous 5.3 milligram filter loading requirement which
is too difficult to achieve with today's low PM emitting engines.
    11. Apply the same proportional sampling requirement to the
Critical Flow Venturi (CFV-CVS) and the Positive Displacement Pump-
Constant Volume Sampler (PDP-CVS) systems (Sec. 86.1310-90(b)(6),
Sec. 86.1337-90(a)(10), Sec. 86.1337-96(a)(10)). This new language
consolidates the requirement for demonstrating, during diesel
particulate testing, sample flow proportionality for both the single-
dilution and double-dilution methods. Prior to the change, PDP-CVS
systems were only required to demonstrate that flow through the
particulate transfer tube was constant, plus or minus five percent. The
CFV-CVS was required to demonstrate that the ratio of main tunnel flow
to particulate sample flow did not change by more than plus or minus
five percent. The requirements for the two CVS systems are the same
assuming that flow through the PDP-CVS does not vary. Since this
assumption is not always true, the proportionality requirements for the
PDP-CVS and the CFV-CVS are not equivalent. To correct this,
laboratories with a PDP-CVS sampling system are required to meet the
same requirements as the CFV-CVS system, which is to demonstrate that
the ratio of main tunnel flow to particulate sample flow did not change
by more than plus or minus five percent.
    12. Clarify the ambient condition requirements for the filter
weighing room (Sec. 86.1312-88(a) (1) & (2)). This new language helps
resolve some inconsistencies between the light-and heavy-duty test
procedures. The new humidity requirement states that the room shall be
maintained at a dew point temperature of 282.5K 3K
(9.4 deg.C 3 deg.C) and a relative humidity of 45%
8%. The ambient temperature requirement in the room is
revised to 295K 3K (22 deg.C 3 deg.C) during
all filter conditioning and weighing.
    13. Allow a change in weight on the reference filters, between
weighings, by an absolute number rather than a percentage of the
nominal filter loading

[[Page 47116]]

(Sec. 86.1312-88(a)(4)). Sample and background filter pairs that are in
the process of stabilization shall be discarded if the average weight
of the reference filter pair changes by more than 40 micrograms. This
change simplifies the old requirement where a 5 percent
change from the nominal filter loading was allowed. EPA considers that
it is better practice to have a filter weight variation requirement
that does not vary with the nominal filter loading since a specific
loading is not required, but is only recommended.
    14. Change in the conditioning room timing requirement
(Sec. 86.1312-88(a)(5)). If any of the environmental conditions in the
conditioning room, as specified in the test procedures, are not met,
then it is required that the filters remain in the conditioning room
for at least one hour after correct conditions are met prior to
weighing. This amendment eliminates a previously unnecessary timing
requirement and adds a new option for manufacturers that gives them
greater flexibility in following the test procedures.
    15. Specify a new ASTM procedure for measuring aromatic composition
in diesel fuel (Sec. 86.1313-91, Sec. 86.1313-94, Sec. 86.1313-98). The
amendment allows, for heavy-duty diesel engines of model years 1987
thru 1997, the use of ASTM procedure D5186-91 for measuring aromatic
composition. For model years 1998 and later, ASTM D5186-91 will be the
required procedure for measuring aromatic composition.
    16. For diesel fuel testing only, change the requirement of
calibrating the CO analyzer to bi-monthly or immediately after
maintenance (Sec. 86.1316-90). This amendment loosens the monthly
calibration requirement due to the typically low levels of CO, relative
to the standard, produced by heavy-duty diesel engines.
    17. Change a requirement to generate new calibration curves each
month (Sec. 86.1316-90, Sec. 86.1316-94). This amendment adds
flexibility to the test procedure by allowing the manufacturer not to
generate a new calibration curve for an analyzer if they have
demonstrated that it has not significantly varied from its last
calibration. This change does not affect the accuracy of the analyzers,
but simplifies the calibration process.
    18. Clarify the method for issuing speed and torque command
setpoints throughout the test cycle (Sec. 86.1327-90(b), Sec. 86.1327-
94(b), Sec. 86.1327-96(b)). The frequency for issuing the command
setpoints for engine torque and speed were not specified in the
original rule. It is now clarified that the torque and speed command
setpoints shall be issued at 5 Hz or greater.
    19. Clarify the exhaust system and insulation requirements for
diesel engines equipped with catalysts (Sec. 86.1327-90(f),
Sec. 86.1327-94(f), Sec. 86.1327-96(f)). These amendments respond to
the need to account for exhaust aftertreatment technology, which is
seeing a wider use in current heavy-duty engines. The language being
added to the regulations specifies that the exhaust pipe diameter shall
be the same as that found in-use. In addition, it is specified that for
gasoline and diesel engines, the catalyst container may be removed
during all test sequences prior to the practice cycle, and replaced
with an equivalent container having an inactive catalyst support. The
reason for allowing such option to manufacturers is that the catalyst
may be consumed by the high exhaust temperatures experienced during
testing. Finally, it is also specified that the distance from the
exhaust manifold flange or turbocharger outlet to any exhaust
aftertreatment device shall be the same as the vehicle configuration or
within the distance specifications that the engine manufacturers
provide for the installation of such devices.
    20. Clarify that loading from accessories is considered parasitic
in nature and that their work shall not be included in the emission
calculations (Sec. 86.1327-98, Sec. 86.1341-98(b)(3)).  The accessory
loading is considered parasitic because it is not providing any
``useful work''. ``Useful work'' is the work that the application (that
uses the engine in question) does when commanded by an operator. The
amendment clarifies that accessories such as oil coolers, alternators,
air compressors, etc., if used, shall be applied to all engine testing
operations. Their work, however, shall not be included in the
integrated work used in emission calculations. This clarification adds
consistency between emission test results from different engines, which
do not necessarily operate with the same accessories.
    21. Require the following of SAE Recommended Practice J1937 for
simulating the use of a charge air cooling device while running the FTP
in a dynamometer test cell (Sec. 86.1330-84(b)(5), Sec. 86.1330-
90(b)(5)). The following of this procedure will help ensure the uniform
use of such devices, which were not of common use when the original
rule was written.
    22. Define new intake and exhaust restriction setting requirements
for diesel fueled heavy-duty engines (Sec. 86.1330-84(f) and
Sec. 86.1330-90(f)). This new language replaces earlier language that
required the manufacturers to demonstrate some average restrictions
that their engines would typically experience in-use. The old
requirements were very difficult to meet. The new requirement for the
air inlet specifies a restriction setting which is midway between a
clean filter and the maximum restriction specified by the manufacturer.
In addition, the new requirement for exhaust restriction is 80 percent
of the manufacturer's recommended maximum specified exhaust
restriction. Furthermore, EPA still holds the manufacturer accountable
for the entire range of restrictions that the engine might experience
in-use.
    23. Correct the temperature requirement of the CVS dilution air
(Sec. 86.1330-84(b), Sec. 86.1330-90(b)). The language added makes the
dilution air temperature requirement consistent with Sec. 86.1310-90,
which is 68 deg.F (20 deg.C) for Otto cycle engines and between
68 deg.F and 86 deg.F (20 deg.C and 30 deg.C) for diesel cycle engines.
    24. Change the required torque command set-points in the FTP that
utilize the provisions related to Curb Idle Torque (CITT)
(Sec. 86.1333-90). The manufacturer is allowed to modify all torque
command set-points to CITT when the speed command set-point is equal to
or less than zero percent and the ``initial'' torque command set-point
is less than CITT. This language corrects a problem where, in certain
cases, a low torque command resulted in a real torque command less than
CITT, which is an operating condition that these engines do not
typically encounter in-use.
    25. Clarify the idle torque requirements for cycle validation
(Sec. 86.1333-90). The existing language for idle torque requirements
is clarified to make it more understandable.
    26. Apply a single set of requirements to both forced and natural
cool downs which precede the cold start exhaust emissions test
(Sec. 86.1334-84 and Sec. 86.1335-90).  This change defines a cold
engine as one with oil and water temperatures between 68 and 86 deg.F.
This is a change from the existing natural cool down requirements which
call for only oil temperature to be stabilized between 68 and 86
deg.F. The temperature requirements for forced cool down are now the
same as for natural cool down, thus providing one definition for a cold
engine regardless of the cool down procedure.
    27. Correct an oversight regarding the first FTP idle definition
(Sec. 86.1337-90 and Sec. 86.1337-96). This amendment adds language to
Sec. 86.1337-90 and Sec. 86.1337-96 that was inadvertently lost

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from Sec. 86.1337-88. It also corrects a paragraph reference in the
same sections and eliminates specifications for particulate testing
without the use of flow compensation because these specifications are
no longer needed since the same particulate sampling requirements now
apply for systems with and without flow compensation.
    28. Clarify the procedure for calibrating gaseous emission
analyzers (Sec. 86.1321-90, Sec. 86.1321-94, Sec. 86.1322-84,
Sec. 86.1323-84, Sec. 86.1324-84 and Sec. 86.1325-94, Sec. 86.1338-84).
The data points requirements for calibrating analyzers below 15 percent
of full scale are specified in order to ensure an accurate curve. The
previous calibration procedure was defined by the type of gas divider
used for the calibration. Not all gas dividers were covered by the
previous procedure and no procedure was provided for a laboratory which
uses gas bottles. Changes to the procedure now allow the generation of
calibration data with six points that are approximately equally spaced.
Finally, analyzer response over 100% of full scale may be used if it
can be shown that readings in this range are accurate. These changes
give more flexibility without affecting the accuracy of the
calibrations.
    29. Require that particulate sample filters be placed in unsealed
petri dishes during conditioning after the emissions test
(Sec. 86.1339-90). This language will help ensure that particulate
filters will be handled consistently in all laboratories and makes it
consistent with the pre-conditioning requirements. The unsealed petri
dish requirement is needed in order to have a uniform method for
handling PM filters that also eliminates the possibility of filter
contamination.
    30. Eliminate the 80 hour maximum for pre-conditioning PM filters
(Sec. 86.1339-90). This change simplifies the filter pre-conditioning
procedure by eliminating the 80 hour maximum time requirement. It was
found that only the minimum 1 hour requirement was of meaningful value
for filter pre-conditioning.
    31. Clarify the permitted point deletions from regression analysis
for validation statistics (Sec. 86.1341-90, Sec. 86.1341-98 and
Appendix I, paragraph (f)(2)). A table that describes the permitted
point deletions from regression analysis is simplified by removing some
language and adding three sentences. The changes will make the table
easier to understand and do not affect test results.
    32. Correct an oversight regarding the calculation of cycle work
(Sec. 1341-90). This clarification adds language to Sec. 86.1341-90
that was inadvertently not included from Sec. 86.1341-84.
    33. Clarify that no useful work is generated from spurious non-
zero/CITT torques that occur during idle (Sec. 86.1341-98(b) (3) &
(4)). For manual transmissions, all spurious non-zero torques at
reference idle portions of the cycle shall be set equal to zero and
included in the horsepower-hour calculation used for emission
determinations. For automatic transmissions, all spurious non-CITT
torques at reference idle portions of the cycle shall be included in
the horsepower-hour calculation used in the emission determination.
    34. Clarify the calculations for converting emission measurements
from as-measured dry concentrations to wet concentrations
(Sec. 86.1342-90, Sec. 86.1342-94). An equation used to convert as-
measured dry concentrations to wet concentrations is amended in order
to correct an error in its derivation.
    35. Correct an error that occurred from Sec. 86.1342-84 to
Sec. 86.1342-90 when some guidelines for converting dry measurements to
wet concentrations became subordinate to a section describing the
calculation of brake-specific fuel consumption (Sec. 86.1342-90,
Sec. 86.1342-94).
    36. Clarify what calculations should be used for determining the
emission of particulate matter depending on what type of CVS sampling
system is used (Sec. 86.1343-88). The original language did not
distinguish between critical flow venturi (CFV) CVS and positive
displacement pump (PDP) CVS, which require different calculations for
determining the mass of particulate matter. The new language now
provides distinct calculations for both systems for emission
calculation purposes.
    37. Add provisions for testing heavy-duty engines and light-duty
vehicles that require the manufacturer to verify that the venturi is
achieving sonic flow when using a CFV-CVS sampling system (Sec. 86.119-
90, Sec. 86.1319-84 and Sec. 86.1319-90). Having sonic flow during
emission tests, when using a CFV-CVS sampling system, is of critical
importance in order to achieve accurate and reliable emission results.
Manufacturers have two options for verifying sonic flow. The first
option involves calculating CFV pressure ratio, which must be less than
or equal to the calibration pressure ratio limit derived from the CFV
calibration data. Other sonic flow verification methods may be allowed
with prior approval from the Administrator.
    38. Revise Incorporation by Reference (Sec. 86.1). Section 86.1
contains a listing of all items in part 86 which are incorporated by
reference, along with the section numbers where they are incorporated.
The SAE Recommended Practice J1937 and the standard test method ASTM
5186-91 are added to such list. In addition, several minor corrections
to section 86.1 are made. In the Gaseous Fuels Rule the changes to
section 86.1 to incorporate the standards ASTM D2163-91 and ASTM D1945-
91 were in some cases incorrect and did not properly list the part 86
sections in which these standards were incorporated.
    39. Correct Certification Specifications for Diesel Fuel for Light-
Duty Vehicles and Trucks (Sec. 86.113-94). In the Gaseous Fuels Rule
(59 FR 48472) the section specifying certification fuel parameters for
light-duty vehicles and trucks (Sec. 86.113-94) was modified to include
natural gas and liquefied petroleum gas specifications. In addition to
new gaseous fuels specifications, this section was restructured to make
future additions of other fuels easier. Although these were the only
intended changes, some changes were inadvertently made to the
specifications for diesel fuel as well. Thus, in this notice such
section is being revised to correct for these inadvertent changes to
the diesel fuel specifications. Corrections involve the cetane number
and cetane index in paragraph (b)(2), and the cetane index, 90 percent
distillation point and gravity in paragraph (b)(3). These changes will
bring the diesel fuel certification specifications back to their
original state, prior to the publication of the Gaseous Fuels Rule.
    40. Clarify Gaseous Fuel Standards Applicability (Sec. 86.094-8,
Sec. 86.094-9, Sec. 86.094-11, Sec. 86.096-8 and Sec. 86.096-11). In
the Gaseous Fuels Rule there were several instances where the
regulatory text did not mirror the preamble discussion concerning the
applicability of various standards to gaseous-fueled vehicles,
especially as they relate to the options on the applicability of the
standards prior to the 1997 model year. EPA is revising the regulatory
text to clarify the provisions of the Gaseous Fuels Rule regulations.
The clarifications are summarized briefly in the following sentences.
In sections 86.094-8, 86.094-9, 86.096-8 and 86.096-11, the language
concerning the crankcase emissions prohibition is being clarified to
show that it is optional for the 1994 through 1996 model years and also
optional for 1997 model year turbocharged gaseous fueled heavy-duty
engines. In sections 86.094-9 and 86.096-11 the language concerning
exhaust emission standards is being

[[Page 47118]]

clarified to show that those standards are optional for gaseous-fueled
vehicles through the 1996 model year. In section 86.094-9 the language
concerning idle carbon monoxide (CO) emission standards is being
clarified to show that those standards are applicable to gaseous-fueled
engines, but optional through the 1996 model year. Finally, the section
86.094-11 language concerning smoke standards is being clarified to
show that those standards are applicable to gaseous-fueled vehicles,
but optional through the 1996 model year.
    41. Clarify Exhaust Emission Calculations Sec. 86.144-94). In
section 86.144-94, the density of nonmethane hydrocarbons in natural
gas and liquefied petroleum gas is used for emission calculations. The
description of this term incorrectly specifies that it be defined
simply as the density of hydrocarbon components in the fuel. This
definition does not exclude methane, as it should. The definition is
being corrected here to refer to the density of only the nonmethane
components.
    42. Clarify Changes to the Flame Ionization Detector (FID)
optimization (Sec. 86.1321-90 and Sec. 86.1321-94). More language is
incorporated to resolve some previous inconsistencies with the
procedure. For instance, the FID response now can be optimized with
respect to fuel flow or to fuel pressure. Furthermore, it is also
clarified that the optimum fuel, air, and sample pressures or flow
rates shall be recorded after their determination.

III. Environmental and Economic Impacts

    EPA believes that these technical amendments will not have any
significant economic or environmental impacts. The changes have the
objective to clarify inconsistencies that might have been present in
the original rule or to allow the use of new testing equipment that
gives more flexibility, but does not affect test results.

IV. Public Participation

    EPA believes that the provisions of this action are
noncontroversial since all the changes to the test procedures have been
previously discussed and resolved with the Engine Manufacturers
Association (EMA) and its members. Nonetheless, if public comments are
to be submitted, the Agency requests that wherever applicable, full
supporting data and detailed analysis should be submitted to allow EPA
to make maximum use of the comments. Commentators should provide
specific suggestions for any changes to any aspect of the regulations
that they believe need to be modified or improved. If EPA receives
adverse or critical comments regarding any specific element of this
rule, EPA will withdraw those regulations for which adverse or critical
comments were received. All comments should be directed to EPA Air
Docket, Docket No. A-96-07. The official comment period will last for
30 days following publication of this notice.
    Commentators desiring to submit proprietary information for
consideration should clearly distinguish such information from other
comments to the greatest extent possible, and clearly label it
``Confidential Business Information''. Submissions containing such
proprietary information should be sent directly to the contact person
listed above, and not to the public docket, to ensure that proprietary
information is not inadvertently placed in the docket.
    Information covered by such a claim of confidentiality will be
disclosed by EPA only to the extent allowed and by the procedures set
forth in 40 CFR part 2. If no claim of confidentiality accompanies the
submission when it is received by EPA, it may be made available to the
public without further notice to the commentator.

V. Statutory Authority

    The statutory authority for this action is granted by Sections 202,
206, 207, 208 and 301(a) of the Clean Air Act.

VI. Administrative Designation and Regulatory Analysis

    Under Executive Order 12866 (58 FR 51735 (October 4, 1993)), the
Agency must determine whether this regulatory action is ``significant
and therefore subject to Office of Management and Budget (OMB) review
and the requirements of the Executive Order. The Order defines
``significant'' regulatory action as one that is likely to result in a
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or
adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local or tribal governments or communities;
    (2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or
    (4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
    Pursuant to the terms of Executive Order 12866, EPA believes that
this action is not a ``significant'' regulatory action within the
meaning of the Executive Order.

VII. Compliance With Regulatory Flexibility Act

    EPA has determined that it is not necessary to prepare a regulatory
flexibility analysis in connection with this final rule. In support of
its proposed rule entitled Control of Emissions of Air Pollution from
Highway Heavy-Duty Engines (61 FR 33421, June 27, 1996), EPA
characterized the heavy-duty engine manufacturing industry in Chapter 3
of its Regulatory Impact Analysis (RIA). Based on that
characterization, EPA has determined that these technical amendments
will not have a significant impact on a substantial number of small
entities.

VIII. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA
must prepare a written statement to accompany any rule where the
estimated costs to State, local, or tribal governments, or to the
private sector will be $100 million or more in any one year. Under
section 205, EPA must select the most cost-effective and least
burdensome alternative that achieves the objective of the rule and that
is consistent with statutory requirements. Section 203 requires EPA to
establish a plan for informing and advising any small governments that
may be significantly and uniquely impacted by the rule. EPA estimates
that the costs to State, local, or tribal governments, or the private
sector, from this rule will be less than $100 million.

IX. Paperwork Reduction Act

    The technical amendments promulgated by this action do not create
or change the information collection burden under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501 et. seq. The Office of
Management and Budget (OMB) has previously approved the information
collection requirements already contained in all the Part 86 sections
amended by this action and has assigned OMB control numbers 2060-0104
and 2060-0064.

X. Submission to Congress and the General Accounting Office

    Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business
Regulatory Enforcement Fairness Act of 1996, EPA

[[Page 47119]]

submitted a report containing this rule and other required information
to the U.S. Senate, the U.S. House of Representatives and the
Comptroller General of the General Accounting Office prior to
publication of this rule in today's Federal Register. This rule is not
a ``major rule'' as defined by 5 U.S.C. 804(2).

XI. Copies of Rulemaking Documents

    The preamble and regulatory language are available in the public
docket as described under ADDRESSES above and is also available
electronically on the Technology Transfer Network (TTN), which is an
electronic bulletin board system (BBS) operated by EPA's Office of Air
Quality Planning and Standards and via the Internet. The service is
free of charge, except for the cost of the phone call.

A. Technology Transfer Network (TTN)

    Users are able to access and download TTN files on their first call
using a personal computer and modem per the following information.

TTN BBS: 919-541-5742 (1200-14400 bps, no parity, 8 data bits, 1 stop
bit)
Voice Helpline: 919-541-5384
Also accessible via Internet: TELNET ttnbbs.rtpnc.epa.gov
Off-line: Mondays from 8:00 AM to 12:00 Noon ET

    A user who has not called TTN previously will first be required to
answer some basic informational questions for registration purposes.
After completing the registration process, proceed through the
following menu choices from the Top Menu to access information on this
rulemaking.

     GATEWAY TO TTN TECHNICAL AREAS (Bulletin Boards)
     OMS--Mobile Sources Information
     Rulemaking & Reporting
    <5> Heavy-duty/Diesel
    <1> File area #1 . . . Heavy-duty Truck and Bus Standards

    At this point, the system will list all available files in the
chosen category in reverse chronological order with brief descriptions.
To download a file, select a transfer protocol that is supported by the
terminal software on your own computer, then set your own software to
receive the file using that same protocol.
    If unfamiliar with handling compressed (i.e. ZIP'ed) files, go to
the TTN top menu, System Utilities (Command: 1) for information and the
necessary program to download in order to unZIP the files of interest
after downloading to your computer. After getting the files you want
onto your computer, you can quit the TTN BBS with the oodbye
command.
    Please note that due to differences between the software used to
develop the document and the software into which the document may be
downloaded, changes in format, page length, etc. may occur.

B. Internet

    Rulemaking documents may be found on the Internet as follows:

World Wide Web: http://www.epa.gov/omswww
FTP: ftp://ftp.epa.gov Then CD to the /pub/gopher/OMS/ directory
Gopher: gopher://gopher.epa.gov:70/11/Offices/Air/OMS

    Alternatively, go to the main EPA gopher, and follow the menus:

gopher.epa.gov
    EPA Offices and Regions
    Office of Air and Radiation
    Office of Mobile Sources

List of Subjects

40 CFR Part 9

    Reporting and recordkeeping requirements.

40 CFR Part 86

    Environmental protection, Administrative practice and procedures,
Air pollution control, Confidential business information, Gasoline,
Incorporation by reference, Labeling, Motor vehicles, Motor vehicle
pollution, Reporting and recordkeeping requirements.

    Dated: August 18, 1997.
Carol M Browner,
Administrator.

    For the reasons set forth in the preamble, parts 9 and 86 of title
40 of chapter I of the Code of Federal Regulations are amended as
follows:

PART 9--[AMENDED]

    1. The authority citation for part 9 continues to read as follows:

    Authority: 7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001, 2003,
2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 348; 31 U.S.C. 9701; 33
U.S.C. 1251 et seq., 1311, 1313d, 1314, 1321, 1326, 1330, 1344, 1345
(d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR 1971-1975 Comp. p.
973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g, 300g-1, 300g-2,
300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2, 300j-3, 300j-4,
300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542, 9601-9657,
11023, 11048.

    1a. Section 9.1 is amended in the table by adding in numerical
order new entries under the center heading ``Control of Air Pollution
from New and In-Use Motor Vehicles and New and In-Use Motor Vehicle
Engines: Certification and Test Procedures,'' to read as follows:

Sec. 9.1  OMB approvals under the Paperwork Reduction Act.

* * * * *


              40 CFR citation                      OMB control no.






* * * * *

Control of Air Pollution From New and In-Use Motor Vehicles and New and
In-Use Motor Vehicle Engines: Certification and Test Procedures

* * * * *

86.1313-98.................................................    2060-0104

                  *        *        *        *        *
86.1327-98.................................................    2060-0104

                  *        *        *        *        *
86.1341-98.................................................    2060-0104

                  *        *        *        *        *


PART 86--CONTROL OF AIR POLLUTION FROM NEW AND IN-USE MOTOR
VEHICLES AND NEW AND IN-USE MOTOR VEHICLE ENGINES: CERTIFICATION
AND TEST PROCEDURES

    1b. The authority citation for part 86 is revised to read as
follows:

    Authority: 42 U.S.C. 7401-7671q.

    2. In Sec. 86.1 the tables in paragraphs (b)(1) and (b)(2) are
amended by adding an entry for ASTM D5186-91 after ASTM E29-90, and by
revising the entries for ASTM D2163-91 and ASTM D1945-91 to read as
follows:

Sec. 86.1  Reference materials.

* * * * *
    (b) * * *
    (1) * * *

------------------------------------------------------------------------
         Document number and name             40 CFR part 86 reference
------------------------------------------------------------------------

              *        *        *        *        *
ASTM D5186-91, Standard Test Method for     86.1313-91, 86.1313-94,
 Determination of Aromatic Content of        86.1313-98.
 Diesel Fuels by Supercritical Fluid
 Chromatography.
ASTM D2163-91, Standard Test Method for     86.113-94; 86.1213-94;
 Analysis of Liquefied Petroleum (LP)        86.1313-94.
 Gases and Propane Concentrates by Gas
 Chromatography.

[[Page 47120]]


ASTM D1945-91, Standard Test Method for     86.113-94; 86.513-94;
 Analysis of Natural Gas By Gas              86.1213-94; 86.1313-94.
 Chromatography.
------------------------------------------------------------------------

    (2) * * *

------------------------------------------------------------------------
           Document No. and name              40 CFR part 86 reference
------------------------------------------------------------------------

              *        *        *        *        *
SAE Recommended Practice J1937, November    86.1330-84; 86.1330-90.
 1989, Engine Testing with Low Temperature
 Charge Air Cooler Systems in a
 Dynamometer Test Cell.
------------------------------------------------------------------------

* * * * *
    3. Section 86.094-8 of subpart A is amended by revising paragraph
(c) to read as follows:

Sec. 86.094-8  Emission standards for 1994 and later model year light-
duty vehicles.

* * * * *
    (c) No crankcase emissions shall be discharged into the ambient
atmosphere from any 1994 and later model year Otto-cycle, or methanol-
or gaseous-fueled diesel light-duty vehicle. This requirement is
optional for 1994 through 1996 model year gaseous-fueled light-duty
vehicles.
* * * * *
    4. Section 86.094-9 of subpart A is amended by revising paragraphs
(a)(1)(i) introductory text, (a)(1)(ii) introductory text, (a)(1)(iii)
and (c), to read as follows:

Sec. 86.094-9  Emission standards for 1994 and later model year light-
duty trucks.

    (a) * * *
    (1) * * *
    (i) Light light-duty trucks. Exhaust emission from 1994 and later
model year light light-duty trucks shall meet all standards in Tables
A94-8, A94-9, A94-11 and A94-12 in the rows designated with the
applicable fuel type and loaded vehicle weight, according to the
implementation schedule in Tables A94-7 and A94-10 as follows (optional
for 1994 through 1996 model year gaseous-fueled light light-duty
trucks):
* * * * *
    (ii) Heavy light-duty trucks. Exhaust emissions from 1994 and later
model year heavy light-duty trucks shall meet all standards in Tables
A94-14 and A94-15 in the rows designated with the applicable fuel type
and loaded vehicle weight or adjusted loaded vehicle weight, as
applicable, according to the implementation schedule in Table A94-13,
as follows (optional for 1994 through 1996 model year gaseous-fueled
heavy light-duty trucks):
* * * * *
    (iii) Exhaust emissions of carbon monoxide from 1994 and later
model year light-duty trucks shall not exceed 0.50 percent of exhaust
gas flow at curb idle at a useful life of 11 years or 120,000 miles,
whichever first occurs (for Otto-cycle, and methanol-and gaseous-fueled
diesel light-duty trucks only--optional for 1994 through 1996 model
year gaseous-fueled light-duty trucks).
* * * * *
    (c) No crankcase emissions shall be discharged into the ambient
atmosphere from any 1994 and later model year light-duty truck. This
requirement is optional for 1994 through 1996 model year gaseous-fueled
light-duty trucks.
* * * * *
    5. Section 86.094-11 of subpart A is amended by revising paragraph
(b)(1) introductory text to read as follows:

Sec. 86.094-11  Emission standards for 1994 and later model year diesel
heavy-duty engines and vehicles.

* * * * *
    (b)(1) The opacity of smoke from new 1994 and later model year
diesel heavy-duty engines shall not exceed (optional for 1994 through
1996 model year gaseous-fueled diesel heavy-duty engines):
* * * * *
    6. Section 86.096-8 of subpart A is amended by revising paragraph
(c) to read as follows:

Sec. 86.096-8  Emission standards for 1996 and later model year light-
duty vehicles.

* * * * *
    (c) No crankcase emissions shall be discharged into the ambient
atmosphere from any 1996 and later model year Otto-cycle, or methanol-
or gaseous-fueled diesel light-duty vehicle. This requirement is
optional for 1996 model year gaseous-fueled light-duty vehicles.
* * * * *
    7. Section 86.096-11 of subpart A is amended by revising paragraphs
(a) introductory text and (c) to read as follows:

Sec. 86.096-11  Emission standards for 1996 and later model year diesel
heavy-duty engines and vehicles.

    (a) Exhaust emissions from new 1996 and later model year diesel
heavy-duty engines shall not exceed the following (optional for 1996
model year gaseous-fueled diesel heavy-duty engines):
* * * * *
    (c) No crankcase emissions shall be discharged into the ambient
atmosphere from any new 1996 or later model year methanol-or gaseous-
fueled diesel, or any naturally aspirated diesel heavy-duty engine. For
petroleum-fueled engines only, this provision does not apply to engines
using turbochargers, pumps, blowers, or superchargers for air
induction. This provision is optional for all 1996 model year gaseous-
fueled diesel heavy-duty engines, and for 1997 model year gaseous-
fueled diesel heavy-duty engines using turbochargers, pumps, blowers or
superchargers for air induction.
* * * * *
    8. Section 86.113-94 of subpart B is amended by revising the tables
after paragraphs (b)(2) and (b)(3) to read as follows:

Sec. 86.113-94  Fuel specifications.

* * * * *
    (b) * * *
    (2) * * *

----------------------------------------------------------------------------------------------------------------
                  Item                                                    ASTM test method No.       Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number...........................  ............................  D613                               40-48
Cetane Index............................  ............................  D976                               40-48
Distillation range:
  IBP...................................   deg.F                        D86                              340-400
                                          ( deg.C)                      .......................    (171.1-204.4)
  10 pct. point.........................   deg.F                        D86                              400-460
                                          ( deg.C)                      .......................    (204.4-237.8)
  50 pct. point.........................   deg.F                        D86                              470-540
                                          ( deg.C)                      .......................    (243.3-282.2)

[[Page 47121]]


  90 pct. point.........................   deg.F                        D86                              560-630
                                          ( deg.C)                      .......................    (293.3-332.2)
  EP....................................   deg.F                        D86                              610-690
                                          ( deg.C)                      .......................    (321.1-365.6)
Gravity.................................   deg.API                      D287                               32-37
Total sulfur............................  pct.                          D2622                          0.03-0.05
Hydrocarbon composition:
  Aromatics, min........................  pct.                          D1319                                 27
  Paraffins, Naphthenes, Olefins........  ............................  D1319                                (1)
Flashpoint, min.........................   deg.F                        D93                                  130
                                          ( deg.C)                      .......................           (54.4)
Viscosity, centistokes..................  ............................  D445                            2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Remainder.

    (3) * * *

----------------------------------------------------------------------------------------------------------------
                  Item                                                    ASTM test method No.       Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number...........................  ............................  D613                               38-58
Cetane Index............................  ............................  D976                             min. 40
Distillation range:
  90 pct. point.........................   deg.F                        D86                              540-630
                                          ( deg.C)                      .......................    (282.2-343.3)
Gravity.................................   deg.API                      D287                               30-39
Total sulfur............................  pct.                          D2622                          0.03-0.05
Flashpoint, min.........................   deg.F                        D93                                  130
                                          ( deg.C)                      .......................           (54.4)
Viscosity...............................  centistokes                   D445                             1.5-4.5
----------------------------------------------------------------------------------------------------------------

* * * * *
    9. Section 86.119-90 of subpart B is amended by revising paragraph
(b)(3) and adding paragraph (b)(8) to read as follows:

Sec. 86.119-90  CVS calibration.

* * * * *
    (b) * * *
    (3) Measurements necessary for flow calibration are as follows:

                                                              Calibration Data Measurements
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Parameter                         Symbol                          Units                                     Tolerances
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected).......  Pb                       Inches Hg (kPa)                       .01 in Hg (.034 kPa).
Air temperature, flowmeter............  ETI                       deg.F ( deg.C)                       .25 deg.F (.14 deg.C).
Pressure depression upstream of LFE...  EPI                      Inches H2O (kPa)                      .05 in H2O (.012 kPa).
Pressure drop across LFE matrix.......  EDP                      Inches H2O (kPa)                      .005 in H2O (.001 kPa).
Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5 pct.
CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa).
CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       0.05 in. Hg (0.17 kPa)
Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       0.5 deg.F (0.28 deg.C).
Specific gravity of manometer fluid     Sp. Gr                   ....................................  .................................................
 (1.75 oil).
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (8) Calculation of a parameter for monitoring sonic flow in the CFV
during exhaust emissions tests:
    (i) Option 1. (A) CFV pressure ratio. Based upon the calibration
data selected to meet the criteria for paragraphs (d)(7)(iv) and (v),
in which Kv is constant, select the data values associated
with the calibration point with the lowest absolute venturi inlet
pressure. With this set of calibration data, calculated the following
CFV pressure ratio limit, Prratio-lim:
[GRAPHIC] [TIFF OMITTED] TR05SE97.000

Where:

Pin-cal=Venturi inlet pressure (PPI in absolute pressure
units), and
Pout-cal=Venturi outlet pressure (PPO in absolute pressure
units), measured at the exit of the venturi diffuser outlet.

    (B) The venturi pressure ratio (Prratio-i) during all
emissions tests must be less than, or equal to, the calibration
pressure ratio limit (Prratio-lim) derived from the CFV
calibration data, such that:
[GRAPHIC] [TIFF OMITTED] TR05SE97.001

Where:

Pin-i and Pout-i are the venturi inlet and outlet
pressures, in absolute

[[Page 47122]]

pressure units, at each i-th interval during the emissions test.

    (ii) Option 2. Other methods: With prior Administrator approval,
any other method may be used that assure that the venturi operates at
sonic conditions during emissions tests, provided the method is based
upon sound engineering principles.
* * * * *
    10. Section 86.144-94 of subpart B is amended by revising paragraph
(c)(8)(ii)(B) to read as follows:

Sec. 86.144-94  Calculations; exhaust emissions.

* * * * *
    (c) * * *
    (8) * * *
    (ii) * * *
    (B) For natural gas and liquefied petroleum gas fuel;
DensityNMHC=1.1771(12.011+H/C(1.008))g/ft3-carbon
atom (0.04157(12.011+H/C(1.008))kg/m3-carbon atom), where H/
C is the hydrogen to carbon ratio of the non-methane hydrocarbon
components of the test fuel, at 68 deg.F (20 deg.C) and 760 mm Hg
(101.3 kPa) pressure.
* * * * *
    11. Section 86.884-7 of subpart I is amended by revising paragraphs
(a)(2)(i), (a)(3) and (a)(4) to read as follows:

Sec. 86.884-7  Dynamometer operation cycle for smoke emission tests.

    (a) * * *
    (1) * * *
    (2) Acceleration mode. (i) The engine speed shall be increased to
200 50 rpm above the measured free idle speed measured at
the point where the throttle begins to move from part-throttle to the
full throttle position. The speed anywhere during this mode should not
exceed this checkpoint speed by more than 50 rpm. The duration of this
first acceleration shall be three seconds or less measured from the
point where the speed first begins to increase above idle to the point
where the throttle reaches full open position.
* * * * *
    (3) Lugging mode. (i) Immediately upon the completion of the
preceding acceleration mode, the dynamometer controls shall be adjusted
to permit the engine to develop maximum horsepower at rated speed. This
transition period shall be 50 to 60 seconds in duration. During the
last 10 seconds of this period, the average engine speed shall be
maintained within 50 rpm of the rated speed, and the average observed
power (corrected, if necessary, to rating conditions) shall be no less
than 95 percent of the maximum horsepower developed during the
preconditioning prior to the smoke cycle.
    (ii) With the throttle remaining in the fully open position, the
dynamometer controls shall be adjusted gradually so that the engine
speed is reduced to the intermediate speed. This lugging operation
shall be performed smoothly over a period of 355 seconds.
The rate of slowing of the engine shall be linear, within 100 rpm, as
specified in Sec. 86.884-13(c).
    (4) Engine unloading. Within five seconds of completing the
preceding lugging mode, the dynamometer and engine controls shall be
returned to the idle position described in paragraph (a)(1) of this
section. The engine must be at free idle condition within one minute
after completion of the lugging mode.
* * * * *
    12. Section 86.884-8 of subpart I is amended by revising paragraph
(c) to read as follows:

Sec. 86.884-8  Dynamometer and engine equipment.

* * * * *
    (c) An exhaust system with an appropriate type of smokemeter placed
10 to 32 feet from the exhaust manifold(s), turbocharger outlet(s),
exhaust aftertreatment device(s), or crossover junction (on Vee
engines), whichever is farthest downstream. The smoke exhaust system
can share the same hardware required in part 86, subpart N,
Sec. 86.1327-84(f)(2), insofar as that hardware also meets the
following smoke test requirements. The smoke exhaust system shall
present an exhaust backpressure within +0.2 inch Hg of the upper limit
at maximum rated horsepower, as established by the engine manufacturer
in his sales and service literature for vehicle application. The
following options may also be used:
    (1) For engines with multiple exhaust outlets, join the exhaust
outlets together into a single exhaust system and install the
smokemeter 10 to 32 feet downstream from the junction of the individual
exhaust outlets, or exhaust aftertreatment device(s), whichever is
farthest downstream.
    (2) For engines with multiple exhaust outlets, install a smokemeter
in each of the exhaust pipes 10 to 32 feet downstream from each exhaust
manifold, turbocharger outlet, or exhaust aftertreatment device,
whichever is farthest downstream.
    (3) For engines with multiple exhaust outlets, install a smokemeter
on the exhaust pipe which produces the highest smoke levels 10 to 32
feet downstream from the exhaust manifold, turbocharger outlet, or
exhaust aftertreatment device, whichever is farthest downstream. It may
be required to make smoke measurements from other exhaust outlets if
deemed appropriate by the Administrator.
    (4) When utilizing an end-of-line smokemeter, the terminal two feet
of the exhaust pipe used for smoke measurement shall be of a circular
cross section and be free of elbows and bends. The end of the pipe
shall be cut off squarely. The terminal two feet of the exhaust pipe
shall have a nominal inside diameter in accordance with the engine
being tested, as specified below:

------------------------------------------------------------------------
                                      Standard Exhaust Pipe Diameter,
     Maximum Rated Horsepower                 inches (meters)
------------------------------------------------------------------------
Less than 101....................  2 (0.051)
101 to 200.......................   3 (0.076)
201 to 300.......................   4 (0.102)
301 to 500.......................   5 (0.127)
501 or more......................  5 (0.127)\1\ or 6 (0.152)\2\
------------------------------------------------------------------------
\1\ Applicable for on-highway engines.
\2\ Applicable for nonroad engines.

    (5) When utilizing an in-line smokemeter, there shall be no change
in the exhaust pipe diameter within 3 exhaust pipe diameters before or
after the centerline of the smokemeter optics. Within 6 exhaust pipe
diameters upstream of the centerline of the smokemeter optics, no
change in exhaust pipe diameter may exceed a 12 degree half-angle.
* * * * *
    13. Section 86.884-9 of subpart I is amended by revising paragraphs
(b)(2)(i), (b)(2)(ii), (b)(2)(iii), (b)(2)(iv), and (c)(1) to read as
follows:

Sec. 86.884-9  Smoke measurement system.

* * * * *
    (b) * * *
    (2) * * *
    (i) It is positioned so that a built-in light beam traverses the
exhaust smoke plume at right angles to the axis of the exhaust stream.
    (ii) The smokemeter light source shall be an incandescent lamp with
a color temperature range of 2800K to 3250K, or a light source with a
spectral peak between 550 to 570 nanometers.
    (iii) The light output is collimated to a beam with a maximum
diameter of 1.125 inches and an included angle of divergence within a
6 deg. included angle.
    (iv) The light detector shall be a photocell or photodiode. If the
light source is an incandescent lamp, the detector shall have a
spectral response similar to the photopic curve of the human eye (a
maximum response in the range of 550 to 570 nanometers, to less than 4
percent of that maximum

[[Page 47123]]

response below 430 nanometers and above 680 nanometers).
* * * * *
    (c) Assembling equipment. (1) The optical unit of the smokemeter
shall be mounted radially to the exhaust pipe so that the measurement
will be made at right angles to the axis of the exhaust plume. For an
end-of-line smokemeter the distance from the optical centerline to the
exhaust pipe outlet shall be 1 0.25 inch. The full flow of
the exhaust stream shall be centered between the source and the
detector apertures (or windows and lenses) and on the axis of the light
beam.
* * * * *
    14. Section 86.884-10 of subpart I is amended by revising paragraph
(a)(8) to read as follows:

Sec. 86.884-10  Information.

* * * * *
    (a) * * *
    (8) Idle rpm.
* * * * *
    15. Section 86.884-13 of subpart I is amended by revising
paragraphs (b)(6)(ii) and (b)(6)(iii) to read as follows:

Sec. 86.884-13  Data analysis.

* * * * *
    (b) * * *
    (6) * * *
    (ii) Average speed during the last 10 seconds shall be within
50 rpm of rated speed.
    (iii) Average observed power during the last 10 seconds shall be at
least 95 percent of the horsepower developed during the preconditioning
mode.
* * * * *
    16. Section 86.884-14 of subpart I is revised to read as follows:

Sec. 86.884-14  Calculations.

    (a) If the measured half-second opacity values were obtained with a
smokemeter with an optical path length different than shown in the
table in Sec. 86.884-8(c), then convert the measured half-second values
or the original instantaneous values to the appropriate equivalent
optical path length values specified in the table. Convert the opacity
values according to the following equations:

Ns=100 x (1-(1-Nm/
100)Ls/Lm)

Lm and Ls must use consistent units in the above
equation

Where:

Nm=Measured half-second value for conversion, percent
opacity
Lm=Measuring smokemeter optical path length, meters
Ls=Standard optical path length corresponding with engine
power, n
Ns=Standard half-second value, percent opacity

    (b) Average the 45 readings in Sec. 86.884-13(d)(3) or the
equivalent converted values from paragraph (a) of this section if
appropriate, and designate the value as ``A''. This is the value for
the engine acceleration mode.
    (c) Average the 15 readings in Sec. 86.884-13(d)(4) or the
equivalent converted values from paragraph (a) of this section if
appropriate, and designate the value as ``B''. This is the value for
the engine lugging mode.
    (d) Average the 9 readings in Sec. 86.884-13(d)(5) or the
equivalent converted values from paragraph (a) of this section if
appropriate, and designate the value as ``C''. This is the value for
the peaks in either mode.
    (e)(1) If multiple smokemeters were used, the half-second values
for each mode from each smokemeter shall be combined and the calculated
average based upon the total number of combined values.
    (2) For example, if two smokemeters were used for acceleration mode
data, 45 half-second values in each data set from both smokemeters
would be combined to form a data set of 90 values, which would then be
averaged.
    17. Section 86.1008-90 of subpart K is amended by adding paragraph
(a)(1)(iii) to read as follows:

Sec. 86.1008-90  Test procedures.

    (a)(1)(i) * * *
    (iii) During the testing of heavy-duty diesel engines, the
manufacturer shall decide for each engine, prior to the start of the
initial cold cycle, whether the measurement of background particulate
is required for the cold and hot cycles to be valid. The manufacturer
may choose to have different requirements for the cold and hot cycles.
If a manufacturer chooses to require the measurement of background
particulate, failure to measure background particulate shall void the
test cycle regardless of the test results. If a test cycle is void, the
manufacturer shall retest using the same validity requirements of the
initial test.
* * * * *
    18. Section 86.1008-96 of subpart K is amended by revising
paragraph (a)(1) to read as follows:

Sec. 86.1008-96  Test procedures

* * * * *
    (a)(1)(i) For heavy-duty engines, the prescribed test procedure is
the Federal Test Procedure, as described in subparts N, I, and P of
this part.
    (ii) During the testing of heavy-duty diesel engines, the
manufacturer shall decide for each engine, prior to the start of the
initial cold cycle, whether the measurement of background particulate
is required for the cold and hot cycles to be valid. The manufacturer
may choose to have different requirements for the cold and hot cycles.
If a manufacturer chooses to require the measurement of background
particulate, failure to measure background particulate shall void the
test cycle regardless of the test results. If a test cycle is void, the
manufacturer shall retest using the same validity requirements of the
initial test.
* * * * *
    19. Section 86.1008-2001 of subpart K is amended by adding
paragraph (a)(1)(iii) to read as follows:

Sec. 86.1008-2001  Test procedures.

    (a)(1)(i) * * *
    (iii) During the testing of heavy-duty diesel engines, the
manufacturer shall decide for each engine, prior to the start of the
initial cold cycle, whether the measurement of background particulate
is required for the cold and hot cycles to be valid. The manufacturer
may choose to have different requirements for the cold and hot cycles.
If a manufacturer chooses to require the measurement of background
particulate, failure to measure background particulate shall void the
test cycle regardless of the test results. If a test cycle is void, the
manufacturer shall retest using the same validity requirements of the
initial test.
* * * * *
    20. Section 86.1111-87 is amended by redesignating paragraph (a)(4)
as paragraph (a)(5) and adding a new paragraph (a)(4) to read as
follows:

Sec. 86.1111-87  Test procedures for PCA testing.

* * * * *
    (a) * * *
    (4) During the testing of heavy-duty diesel engines, the
manufacturer shall decide for each engine, prior to the start of the
initial cold cycle, whether the measurement of background particulate
is required for the cold and hot cycles to be valid. The manufacturer
may choose to have different requirements for the cold and hot cycles.
If a manufacturer chooses to require the measurement of background
particulate, failure to measure background particulate shall void the
test cycle regardless of the test results. If a test cycle is void, the
manufacturer shall retest using the same validity requirements of the
initial test.
* * * * *
    21. Section 86.1310-90 of subpart N is amended by revising
paragraphs (b)(1)(iv)(C), (b)(3)(v), (b)(3)(vi), (b)(6)

[[Page 47124]]

introductory text, and (b)(7)(iv) to read as follows:

Sec. 86.1310-90  Exhaust gas sampling and analytical system; diesel
engines.

* * * * *
    (b) * * *
    (1) * * *
    (iv) * * *
    (C) Primary dilution air may be sampled to determine background
particulate levels, which can then be subtracted from the values
measured in the diluted exhaust stream. The primary dilution air shall
be sampled at the inlet to the primary dilution tunnel, if unfiltered,
or downstream of any primary dilution air conditioning devices, if
used.
* * * * *
    (3) * * *
    (v) The continuous HC sampling system shall consist of a probe
(which must raise the sample to the specified temperature) and, where
used, a sample transfer system (which must maintain the specified
temperature). The continuous hydrocarbon sampling system (exclusive of
the probe) shall:
    (A) Maintain a wall temperature of 464K  11K (191 deg.C
 11 deg.C) as measured at every separately controlled
heated component (i.e., filters, heated line sections), using permanent
thermocouples located at each of the separate components.
    (B) Have a wall temperature of 464K  11K (191 deg.C
 11 deg.C) over its entire length. The temperature of the
system shall be demonstrated by profiling the thermal characteristics
of the system at initial installation and after any major maintenance
performed on the system. The temperature profile of the HC sampling
system shall be demonstrated by inserting thermocouple wires (typically
Teflon coated for ease of insertion) into the sampling
system assembled in-situ where possible, using good engineering
judgement. The wire should be inserted up to the HFID inlet. Stabilize
the sampling system heaters at normal operating temperatures. Withdraw
the wires in increments of 5 cm to 10 cm (2 inches to 4 inches)
including all fittings. Record the stabilized temperature at each
position. The system temperature will be monitored during testing at
the locations and temperature described in Sec. 86.1310-90(b)(v)(A).
Comment: It is understood that profiling of the sample line can be done
under flowing conditions also as required with the probe.
    (C) Maintain a gas temperature of 464K 11K (191 deg.C
11 deg.C) immediately before the heated filter and HFID.
These gas temperatures will be determined by a temperature sensor
located immediately upstream of each component.
    (vi) The continuous hydrocarbon sampling probe shall:
    (A) Be defined as the first 25.4 cm (10 in) to 76.2 cm (30 in) of
the continuous hydrocarbon sampling system.
    (B) Have a 0.483 cm (0.19 in) minimum inside diameter.
    (C) Be installed in the primary dilution tunnel at a point where
the dilution air and exhaust are well mixed (i.e., approximately 10
tunnel diameters downstream of the point where the exhaust enters the
dilution tunnel).
    (D) Be sufficiently distant (radially) from other probes and the
tunnel wall so as to be free from the influence of any wakes or eddies.
    (E) Increase the gas stream temperature to 464K 11K
(191 deg.C 11 deg.C) by the exit of the probe. The ability
of the probe to accomplish this shall be demonstrated at typical sample
flow rates using the insertion thermocouple technique at initial
installation and after any major maintenance. Compliance with the
temperature specification shall be demonstrated by monitoring during
each test the temperature of either the gas stream or the wall of the
sample probe at its terminus.
* * * * *
    (6) Particulate sampling system. The particulate collection system
must be configured in either of two ways. The single-dilution method
collects a proportional sample from the primary tunnel, and then passes
this sample through the collection filter. The double-dilution method
collects a proportional sample from the primary tunnel, and then
transfers this sample to a secondary dilution tunnel where the sample
is further diluted; the double-diluted sample is then passed through
the collection filter. Proportionality (i.e., mass flow ratio) between
the primary tunnel flow rate and the sample flow rate must be
maintained within 5 percent. The requirements for these two
systems are:
* * * * *
    (7) * * *
    (iv) It is recommended that the filter loading should be maximized
consistent with other temperature requirements and the requirement to
avoid moisture condensation. A filter pair loading of 1 mg is typically
proportional to a 0.1 g/bhp-hr emission level. All particulate filters,
reference filters, and background filters shall be handled in pairs
during all weighing operations for emissions testing.
* * * * *
    22. Section 86.1312-88 of subpart N is amended by revising
paragraph (a) to read as follows:

Sec. 86.1312-88  Weighing chamber and microgram balance specifications.

    (a) Ambient conditions. (1) Temperature. The ambient temperature of
the chamber (or room) in which the particulate filters are conditioned
and weighed shall be maintained at 295 K  3 K (22  deg.C
 3  deg.C) during all filter conditioning and weighing.
    (2) Humidity. The humidity of the chamber (or room) in which the
particulate filters are conditioned and weighed shall be maintained at
a dew point temperature of 282.5 K  3 K (9.4  deg.C
 3  deg.C) and a relative humidity of 45% 8%.
Either the dew point temperature or the relative humidity or both may
be averaged over the preceding 10 minute period on a moving average
basis.
    (3) The chamber (or room) environment shall be free of any ambient
contaminates (such as dust) that would settle on the particulate
filters during their stabilization. It is required that at least two
unused reference filter pairs remain in the weighing room at all times
in covered (to reduce dust contamination) but unsealed (to permit
humidity exchange) petri dishes. These reference filter pairs shall be
placed in the same general area as the sample filters. These reference
filter pairs shall be weighed within 4 hours of, but preferably at the
same time as, the sample filter pair weighings.
    (4) If the average weight of the reference filter pairs changes
between sample filter weighings by more than 40 micrograms, then all
sample filters and background filters in the process of stabilization
shall be discarded and the emissions tests repeated.
    (5) If the room (or chamber) environmental conditions are not met,
then the filters shall remain in the conditioning room for at least one
hour after correct conditions are met prior to weighing.
    (6) The reference filter pairs shall be changed at least once a
month, but never between clean and used weighings of a given sample
filter pairs. More than one set of reference filter pair may be used.
The reference filters shall be the same size and material as the sample
filters.
* * * * *
    23. Section 86.1313-91 of subpart N is amended by revising
paragraph (b)(2) including Table N91-2 to read as follows:

Sec. 86.1313-91  Fuel specifications.

* * * * *

[[Page 47125]]

    (b) * * *
    (2) Petroleum fuel for diesel engines meeting the specifications in
Table N91-2, or substantially equivalent specifications approved by the
Administrator, shall be used in exhaust emissions testing. The grade of
petroleum fuel used shall be commercially designated as ``Type 2-D''
grade diesel fuel except that fuel commercially designated as ``Type 1-
D'' grade diesel fuel may be substituted provided that the manufacturer
has submitted evidence to the Administrator demonstrating to the
Administrator's satisfaction that this fuel will be the predominant in-
use fuel. Such evidence could include such things as copies of signed
contracts from customers indicating the intent to purchase and use
``Type 1-D'' grade diesel fuel as the primary fuel for use in the
engines or other evidence acceptable to the Administrator.

                                                   Table N91-2
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          48-54             42-50
Cetane Index.............................  D86                                           40-54             40-48
Distillation range:
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.08-0.12         0.08-0.12
Hydrocarbon composition:
    Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )
Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.
\2\ Remainder.

* * * * *
    24. Section 86.1313-94 of subpart N is amended by revising
paragraph (b)(2) including Table N94-2 to read as follows:

Sec. 86.1313-94  Fuel specifications.

* * * * *
    (b) * * *
    (2) Petroleum fuel for diesel engines meeting the specifications in
Table N94-2, or substantially equivalent specifications approved by the
Administrator, shall be used in exhaust emissions testing. The grade of
petroleum fuel used shall be commercially designated as ``Type 2-D''
grade diesel fuel except that fuel commercially designated at ``Type 1-
D'' grade diesel fuel may be substituted provided that the manufacturer
has submitted evidence to the Administrator demonstrating to the
Administrator's satisfaction that this fuel will be the predominant in-
use fuel. Such evidence could include such things as copies of signed
contracts from customers indicating the intent to purchase and use
``Type 1-D'' grade diesel fuel as the primary fuel for use in the
engines or other evidence acceptable to the Administrator.

                                                   Table N94-2
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          40-54             40-48
Cetane Index.............................  D976                                          40-54             40-48
Distillation range:
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  (187.8-221.1)                         (204.4-237.8)
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
Hydrocarbon composition:
    Aromatics, pct.......................  D1319 or D5186                                \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                       ( \2\ )           ( \2\ )

[[Page 47126]]


Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.
\2\ Remainder.

* * * * *
    25. Section 86.1313-98 is added to subpart N to read as follows:

Sec. 86.1313-98  Fuel specifications.

    Section 86.1313-98 includes text that specifies requirements that
differ from Sec. 86.1313-94. Where a paragraph in Sec. 86.1313-94 is
identical and applicable to Sec. 86.1313-98, this may be indicated by
specifying the corresponding paragraph and the statement ``[Reserved].
For guidance see Sec. 86.1313-94''.
    (a) through (b)(1) [Reserved]. For guidance see Sec. 86.1313-94.
    (b)(2) Petroleum fuel for diesel engines meeting the specifications
in Table N98-2, or substantially equivalent specifications approved by
the Administrator, shall be used in exhaust emissions testing. The
grade of petroleum fuel used shall be commercially designated as ``Type
2-D'' grade diesel fuel except that fuel commercially designated at
``Type 1-D'' grade diesel fuel may be substituted provided that the
manufacturer has submitted evidence to the Administrator demonstrating
to the Administrator's satisfaction that this fuel will be the
predominant in-use fuel. Such evidence could include such things as
copies of signed contracts from customers indicating the intent to
purchase and use ``Type 1-D'' grade diesel fuel as the primary fuel for
use in the engines or other evidence acceptable to the Administrator.

                                                   Table N98-2
----------------------------------------------------------------------------------------------------------------
                   Item                                   ASTM                    Type 1-D          Type 2-D
----------------------------------------------------------------------------------------------------------------
Cetane Number............................  D613                                          40-54             40-48
Cetane Index.............................  D976                                          40-54             40-48
Distillation range:
    IBP  deg.F...........................  D86                                         330-390           340-400
    ( deg.C).............................  .................................     (165.6-198.9)     (171.1-204.4)
    10 percent point,  deg.F.............  D86                                         370-430           400-460
    ( deg.C).............................  .................................     (187.8-221.1)     (204.4-237.8)
    50 percent point,  deg.F.............  D86                                         410-480           470-540
    ( deg.C).............................  .................................       (210-248.9)     (243.3-282.2)
    90 percent point,  deg.F.............  D86                                         460-520           560-630
    ( deg.C).............................  .................................     (237.8-271.1)     (293.3-332.2)
    EP,  deg.F...........................  D86                                         500-560           610-690
    ( deg.C).............................  .................................     (260.0-293.3)     (321.1-365.6)
Gravity,  deg.API........................  D287                                          40-44             32-37
Total Sulfur, percent....................  D2622                                     0.03-0.05         0.03-0.05
Hydrocarbon composition:
    Aromatics, pct.......................  D5186                                         \1\ 8            \1\ 27
    Paraffins, Naphthenes, Olefins.......  D1319                                         (\2\)             (\2\)
Flashpoint,  deg.F.......................  D93                                             120               130
    ( deg.C).............................  .................................            (48.9)            (54.4)
    (minimum)............................  .................................  ................  ................
Viscosity, Centistokes...................  D445                                        1.6-2.0           2.0-3.2
----------------------------------------------------------------------------------------------------------------
\1\ Minimum.
\2\ Remainder.

    (b)(3) through (e) [Reserved]. For guidance see Sec. 86.1313-94.
    26. Section 86.1316-90 of subpart N is amended by revising
paragraph (b)(1) and adding paragraph (f) to read as follows:

Sec. 86.1316-90  Calibrations; frequency and overview.

* * * * *
    (b) * * *
    (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer,
carbon monoxide analyzer, oxides of nitrogen analyzer, methanol
analyzer and formaldehyde analyzer (certain analyzers may require more
frequent calibration depending on the equipment and use). New
calibration curves need not be generated each month if the existing
curve meets the requirements of Secs. 86.1321 through 86.1324.
* * * * *
    (f) For diesel fuel testing only. The carbon monoxide analyzer
shall be calibrated at least every two months or after any maintenance
which could alter calibration.
    27. Section 86.1316-94 of subpart N is amended by revising
paragraph (b)(1) and adding paragraph (f) to read as follows:

Sec. 86.1316-94  Calibrations; frequency and overview.

* * * * *
    (b) * * *
    (1) Calibrate the hydrocarbon analyzer, carbon dioxide analyzer,
carbon monoxide analyzer, and oxides of nitrogen analyzer (certain
analyzers may require more frequent calibration depending on the
equipment and use).

[[Page 47127]]

New calibration curves need not be generated each month if the existing
curve meets the requirements of Secs. 86.1321 through 86.1324.
* * * * *
    (f) For diesel fuel testing only. The carbon monoxide analyzer
shall be calibrated at least every two months or after any maintenance
which could alter calibration.
    28. Section 86.1319-84 of subpart N is amended by revising
paragraph (d)(3) and adding paragraph (d)(8) to read as follows:

Sec. 86.1319-84  CVS calibration.

* * * * *
    (d) * * *
    (3) Measurements necessary for flow calibration are as follows:

                                                              Calibration Data Measurements
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Parameter                         Symbol                          Units                                     Tolerances
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected).......  Pb                       Inches Hg (kPa)                       .01 in Hg (.034 kPa).
Air temperature, flowmeter............  ETI                       deg.F ( deg.C)                       .25  deg.F (.14  deg.C).
Pressure depression upstream of LFE...  EPI                      Inches H2O (kPa)                      .05 in H2O (.012 kPa).
Pressure drop across LFE matrix.......  EDP                      Inches H2O (kPa)                      .005 in H2O (.001 kPa).
Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5 pct.
CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa).
CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       .05 in Hg (0.17 kPa).
Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       0.5  deg.F (0.28  deg.C).
Specific gravity of manometer fluid     Sp. Gr
 (1.75 oil).
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (8) Calculation of a parameter for monitoring sonic flow in the CFV
during exhaust emissions tests:
    (i) Option 1. (A) CFV pressure ratio. Based upon the calibration
data selected to meet the criteria for paragraphs (d)(7)(iv) and (v) of
this section, in which Kv is constant, select the data
values associated with the calibration point with the lowest absolute
venturi inlet pressure. With this set of calibration data, calculated
the following CFV pressure ratio limit, Prratio-lim:
[GRAPHIC] [TIFF OMITTED] TR05SE97.002

where:

Pin-cal=Venturi inlet pressure (PPI in absolute pressure
units), and
Pout-cal=Venturi outlet pressure (PPO in absolute pressure
units), measured at the exit of the venturi diffuser outlet.

    (B) The venturi pressure ratio (Prratio-i) during all
emissions tests must be less than, or equal to, the calibration
pressure ratio limit (Prratio-lim) derived from the CFV
calibration data, such that:
[GRAPHIC] [TIFF OMITTED] TR05SE97.003

Where:

Pin-i and Pout-i are the venturi inlet and outlet
pressures, in absolute pressure units, at each i-th interval during the
emissions test.

    (ii) Option 2. Other methods: With prior Administrator approval,
any other method may be used that assure that the venturi operates at
sonic conditions during emissions tests, provided the method is based
upon sound engineering principles.
* * * * *
    29. Section 86.1319-90 of subpart N is amended by revising
paragraph (d)(3) and adding paragraph (d)(8) to read as follows:

Sec. 86.1319-90  CVS calibration.

* * * * *
    (d) * * *
    (3) Measurements necessary for flow calibration are as follows:

                                                              Calibration Data Measurements
--------------------------------------------------------------------------------------------------------------------------------------------------------
               Parameter                         Symbol                          Units                             Sensor-readout tolerances
--------------------------------------------------------------------------------------------------------------------------------------------------------
Barometric pressure (corrected).......  Pb                       in Hg (kPa)                           .01 in Hg (.034 kPa).
Air temperature, into flowmeter.......  ETI                       deg.F( deg.C)                        0.5  deg.F (0.28  deg.C).
Pressure drop between the inlet and     EDP                      Inches H2O (kPa)                      0.05 in H2O (0.012 kPa).
 throat of metering venturi.
Air flow..............................  Qs                       Ft3/min. (m3/min,)                    .5% of NBS ``true'' value
CFV inlet depression..................  PPI                      Inches fluid (kPa)                    .13 in fluid (.055 kPa).
CFV outlet pressure...................  PPO                      Inches Hg (kPa)                       .05 in Hg (.17 kPa).
Temperature at venturi inlet..........  Tv                        deg.F ( deg.C)                       4.0  deg.F (2.22  deg.C).
Specific gravity of manometer fluid     Sp. Gr
 (1.75 oil).
--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * *
    (8) Calculation of a parameter for monitoring sonic flow in the CFV
during exhaust emissions tests:
    (i) Option 1. (A) CFV pressure ratio. Based upon the calibration
data selected to meet the criteria for paragraphs (d)(7) (iv) and (v)
of this section, in which Kv is constant, select the data
values associated with the calibration point with the lowest absolute
venturi inlet pressure. With this set of calibration data, calculated
the following CFV pressure ratio limit, Prratio-lim:
[GRAPHIC] [TIFF OMITTED] TR05SE97.004

Where:

Pin-cal=Venturi inlet pressure (PPI in absolute pressure
units), and
Pout-cal=Venturi outlet pressure (PPO in absolute pressure
units), measured at the exit of the venturi diffuser outlet.

    (B) The venturi pressure ratio (Prratio-i) during all
emissions tests must be less than, or equal to, the calibration
pressure ratio limit (Prratio-lim) derived from the CFV
calibration data, such that:
[GRAPHIC] [TIFF OMITTED] TR05SE97.005

Where:

[[Page 47128]]

Pin-i and Pout-i are the venturi inlet and outlet
pressures, in absolute pressure units, at each i-th interval during the
emissions test.

    (ii) Option 2. Other methods: With prior Administrator approval,
any other method may be used that assure that the venturi operates at
sonic conditions during emissions tests, provided the method is based
upon sound engineering principles.
* * * * *
    30. Section 86.1321-90 of subpart N is amended by revising
paragraphs (a) and (b)(3) to read as follows:

Sec. 86.1321-90  Hydrocarbon analyzer calibration.

* * * * *
    (a) Initial and periodic optimization of detector response. Prior
to introduction into service and at least annually thereafter, the FID
hydrocarbon analyzer shall be adjusted for optimum hydrocarbon
response.
    (1) Follow good engineering practices for initial instrument start-
up and basic operating adjustment using the appropriate fuel (see
Sec. 86.1314) and zero-grade air.
    (2) Optimize the FID's response on the most common operating range.
The response is to be optimized with respect to fuel pressure or flow
while meeting the analyzer response time given in
Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall
be made to minimize response variations to different hydrocarbon
species that are expected to be in the exhaust. Good engineering
judgement is to be used to trade off optimal FID response to propane-
in-air against reductions in relative responses to other hydrocarbons.
A good example of trading off response on propane for relative
responses to other hydrocarbon species is given in Society of
Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame
Ionization Detector for Determination of Hydrocarbon in Diluted
Automotive Exhausts''; author Glenn D. Reschke. It is also required
that the response be set to optimum condition with respect to air flow
and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at
their specified operating temperature.
    (3) One of the following procedures is to be used for FID or HFID
optimization:
    (i) Use the procedures outlined in Society of Automotive Engineers
(SAE) paper No. 770141, ``Optimization of Flame Ionization Detector for
Determination of Hydrocarbons in Diluted Automobile Exhaust''; author,
Glenn D. Reschke, as an example.
    (ii) The HFID optimization procedures outlined in 40 CFR part 86,
subpart D, Sec. 86.331-79(c).
    (iii) Alternative procedures may be used if approved in advance by
the Administrator.
    (iv) The procedures specified by the manufacturer of the FID or
HFID.
    (4) After the optimum fuel, air, and sample pressures or flow rates
have been determined, they shall be recorded for future reference.
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, propane-in-air calibration gases (e.g.,
15, 30, 45, 60, 75, and 90 percent of that range). For each range
calibrated, if the deviation from a least-squares best-fit straight
line is within 2 percent of the value at each non-zero data
point and within 0.3 percent of full scale on the zero data
point, then concentration values may be calculated by using the linear
calibration equation for that range. If the deviation exceeds these
limits, then the best-fit non-linear equation which represents the data
within these limits shall be used to determine concentration values.
* * * * *
    31. Section 86.1321-94 of subpart N is amended by revising
paragraphs (a) and (b)(3) to read as follows:

Sec. 86.1321-94  Hydrocarbon analyzer calibration.

* * * * *
    (a) Initial and periodic optimization of detector response. Prior
to introduction into service and at least annually thereafter, the FID
hydrocarbon analyzer shall be adjusted for optimum hydrocarbon
response.
    (1) Follow good engineering practices for initial instrument start-
up and basic operating adjustment using the appropriate fuel (see
Sec. 86.1314) and zero-grade air.
    (2) Optimize the FID's response on the most common operating range.
The response is to be optimized with respect to fuel pressure or flow
while meeting the analyzer response time given in
Sec. 86.1310(b)(3)(vii)(A) for continuous HC measurement. Efforts shall
be made to minimize response variations to different hydrocarbon
species that are expected to be in the exhaust. Good engineering
judgement is to be used to trade off optimal FID response to propane-
in-air against reductions in relative responses to other hydrocarbons.
A good example of trading off response on propane for relative
responses to other hydrocarbon species is given in Society of
Automotive Engineers (SAE) Paper No. 770141, ``Optimization of Flame
Ionization Detector for Determination of Hydrocarbon in Diluted
Automotive Exhausts''; author Glenn D. Reschke. It is also required
that the response be set to optimum condition with respect to air flow
and sample flow. Heated Flame Ionization Detectors (HFIDs) must be at
their specified operating temperature.
    (3) One of the following procedures is to be used for FID or HFID
optimization:
    (i) Use the procedures outlined in Society of Automotive Engineers
(SAE) paper number 770141, ``Optimization of Flame Ionization Detector
for Determination of Hydrocarbons in Diluted Automobile Exhaust'';
author, Glenn D. Reschke, as an example. Available from Society of
Automotive Engineers International, 400 Commonwealth Dr., Warrendale,
PA 15096-0001.
    (ii) The procedure listed in subpart D, Sec. 86.331-79(c) of this
part.
    (iii) The procedures specified by the manufacturer of the FID or
HFID.
    (iv) Alternative procedures may be used if approved in advance by
the Administrator.
    (4) After the optimum fuel, air and sample pressures or flow rates
have been determined, they shall be recorded for future reference.
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, propane-in-air calibration gases (e.g.,
15, 30, 45, 60, 75, and 90 percent of that range). For each range
calibrated, if the deviation from a least-squares best-fit straight
line is within 2 percent of the value at each non-zero data
point and within 0.3 percent of full scale on the zero data
point, then concentration values may be calculated by using the linear
calibration equation for that range. If the deviation exceeds these
limits, then the best-fit non-linear equation which represents the data
within these limits shall be used to determine concentration values.
* * * * *
    32. Section 86.1322-84 of subpart N is amended by revising
paragraph (b)(3) to read as follows:

Sec. 86.1322-84  Carbon monoxide analyzer calibration.

* * * * *
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, carbon monoxide-in-N2
calibration gases (e.g., 15, 30, 45, 60, 75, and 90 percent of that
range). For each range calibrated, if the deviation from a least-
squares best-fit straight line is within 2 percent of the

[[Page 47129]]

value at each non-zero data point and within 0.3 percent of
full scale on the zero data point, then concentration values may be
calculated by using the linear calibration equation for that range. If
the deviation exceeds these limits, then the best-fit not-linear
equation which represents the data within these limits shall be used to
determine concentration values.
* * * * *
    33. Section 86.1323-84 of subpart N is amended by revising
paragraph (b)(3) to read as follows:

Sec. 86.1323-84  Oxides of nitrogen analyzer calibration.

* * * * *
    (b) * * *
    (3) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, NO-in-N2 calibration gases
(e.g., 15, 30, 45, 60, 75, and 90 percent of that range). For each
range calibrated, if the deviation from a least-squares best-fit
straight line is within 2 percent of the value at each non-
zero data point and within 0.3 percent of full scale on the
zero data point, then concentration values may be calculated using the
linear calibration equation for that range. If the deviation exceeds
these limits, then the best-fit non-linear equation which represents
the data within these limits shall be used to determine concentration
values.
* * * * *
    34. Section 86.1324-84 of subpart N is amended by revising
paragraph (c) to read as follows:

Sec. 86.1324-84  Carbon dioxide analyzer calibration.

* * * * *
    (c) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, carbon dioxide-in-N2
calibration or span gases (e.g., 15, 30, 45, 60, 75, and 90 percent of
that range). For each range calibrated, if the deviation from a least-
squares best-fit straight line is within 2 percent or less
of the value at each non-zero data point and within 0.3
percent of full scale on the zero data point, then concentration values
may be calculated by using the linear calibration equation for that
range. If the deviation exceeds these limits, then the best-fit non-
linear equation which represents the data within these limits shall be
used to determine concentration values.
* * * * *
    35. Section 86.1325-94 of subpart N is amended by revising
paragraph (c) to read as follows:

Sec. 86.1325-94  Methane analyzer calibration.

* * * * *
    (c) Calibrate on each used operating range with a minimum of 6,
approximately equally spaced, CH4 in air calibration gases (e.g., 15,
40, 45, 60, 75, and 90 percent of that range). For each range
calibrated, if the deviation from a least-squares best-fit straight
line is within 2 percent of the value at each non-zero data
point and within 0.3 percent of full scale on the zero data
point, then concentration values may be calculated by using the linear
calibration equation for that range. If the deviation exceeds these
limits, then the best-fit non-linear equation which represents the data
within these limits shall be used to determine concentration values.
    36. Section 86.1327-90 of subpart N is amended by revising

as follows:

Sec. 86.1327-90  Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5
(10 Hz recommended) Hz or greater during both the cold and hot start
tests. Feedback engine torque and rpm shall be recorded at least once
every second during the test.
* * * * *
    (f) * * *
    (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A
chassis-type exhaust system shall be used. For all catalyst systems,
the distance from the exhaust manifold flange(s) to the catalyst shall
be the same as in the vehicle configuration unless the manufacturer
provides data showing equivalent performance at another location. The
catalyst container may be removed during all test sequences prior to
the practice cycle, and replaced with an equivalent container having an
inactive catalyst support.
    (2) Petroleum-fueled and methanol-fueled diesel engines. Either a
chassis-type or a facility-type exhaust system or both systems
simultaneously may be used. If the engine is equipped with an exhaust
aftertreatment device, the exhaust pipe must be the same diameter as
found in-use for at least 4 pipe diameters upstream to the inlet of the
beginning of the expansion section containing the aftertreatment
device. The exhaust backpressure or restriction shall follow the same
criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler
omitted). The catalyst container may be removed during all test
sequences prior to the practice cycle, and replaced with an equivalent
container having an inactive catalyst support.
    (i) The engine exhaust system shall meet the following
requirements:
    (A) The total length of the tubing from the exit of the engine
exhaust manifold, turbocharger outlet or aftertreatment device to the
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a
typical in-use (i.e., length, diameter, material, etc.) chassis-type
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or
turbocharger outlet to any exhaust aftertreatment device shall be the
same as in the vehicle configuration or within the distance
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the
turbocharger or exhaust manifold shall be insulated. For engines
equipped with exhaust aftertreatment devices, all tubing after the
aftertreatment device which is in excess of 12 feet (3.7 m) shall be
insulated.
    (E) If the tubing is required to be insulated, the radial thickness
of the insulation must be at least 1.0 inch (25 mm). The thermal
conductivity of the insulating material must have a value no greater
than 0.75 BTU-in/hr/ft\2\/ deg.F (0.065 W/m-K) measured at 700  deg.F
(371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the
exhaust system tubing. If this option is exercised in the insulated
portion of the tubing, then a minimal amount of tubing not to exceed 18
inches may be left uninsulated. However, no more than 12 feet (3.66 m)
of tubing can be left uninsulated in total, including the length at the
smoke meter.
* * * * *
    37. Section 86.1327-94 of subpart N is amended by revising
paragraphs (b), (f)(1), (f)(2) introductory text and (f)(2)(i) to read
as follows:

Sec. 86.1327-94  Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5
(10 Hz recommended) Hz or greater during both the cold and hot start
tests. Feedback engine torque and rpm shall be recorded at least once
every second during the test.
* * * * *
    (f) * * *
    (1) Otto-cycle engines. A chassis-type exhaust system shall be
used. For all catalyst systems, the distance from the exhaust manifold
flange(s) to the catalyst shall be the same as in the

[[Page 47130]]

vehicle configuration unless the manufacturer provides data showing
equivalent performance at another location. The catalyst container may
be removed during all test sequences prior to the practice cycle, and
replaced with an equivalent container having an inactive catalyst
support.
    (2) Diesel engines. Either a chassis-type or a facility-type
exhaust system or both systems simultaneously may be used. If the
engine is equipped with an exhaust aftertreatment device, the exhaust
pipe must be the same diameter as found in-use for at least 4 pipe
diameters upstream to the inlet of the beginning of the expansion
section containing the aftertreatment device. The exhaust backpressure
or restriction shall follow the same criteria as in Sec. 86.1330-90 (f)
and may be set with a valve (muffler omitted). The catalyst container
may be removed during all test sequences prior to the practice cycle,
and replaced with an equivalent container having an inactive catalyst
support.
    (i) The engine exhaust system shall meet the following
requirements:
    (A) The total length of the tubing from the exit of the engine
exhaust manifold, turbocharger outlet or aftertreatment device to the
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a
typical in-use (i.e., length, diameter, material, etc.) chassis-type
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or
turbocharger outlet to any exhaust aftertreatment device shall be the
same as in the vehicle configuration or within the distance
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the
turbocharger or exhaust manifold shall be insulated. For engines
equipped with exhaust aftertreatment devices, all tubing after the
aftertreatment device which is in excess of 12 feet (3.7 m) shall be
insulated.
    (E) If the tubing is required to be insulated, the radial thickness
of the insulation must be at least 1.0 inch (25 mm). The thermal
conductivity of the insulating material must have a value no greater
than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700
 deg.F (371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the
exhaust system tubing. If this option is exercised in the insulated
portion of the tubing, then a minimal amount of tubing not to exceed 18
inches may be left uninsulated. However, no more than 12 feet (3.66 m)
of tubing can be left uninsulated in total, including the length at the
smoke meter.
* * * * *
    38. Section 86.1327-96 of Subpart N is amended by revising
paragraphs (b), (f)(1), (f)(2) introductory text, and (f)(2)(i) to read
as follows:

Sec. 86.1327-96   Engine dynamometer test procedures; overview.

* * * * *
    (b) Engine torque and rpm command set points shall be issued at 5
(10 Hz recommended) Hz or greater during both the cold and hot start
tests. Feedback engine torque and rpm shall be recorded at least once
every second during the test.
* * * * *
    (f) * * *
    (1) Gasoline-fueled and methanol-fueled Otto-cycle engines. A
chassis-type exhaust system shall be used. For all catalyst systems,
the distance from the exhaust manifold flange(s) to the catalyst shall
be the same as in the vehicle configuration unless the manufacturer
provides data showing equivalent performance at another location. The
catalyst container may be removed during all test sequences prior to
the practice cycle, and replaced with an equivalent container having an
inactive catalyst support.
    (2) Petroleum-fueled and methanol-fueled diesel engines. Either a
chassis-type or a facility-type exhaust system or both systems
simultaneously may be used. If the engine is equipped with an exhaust
aftertreatment device, the exhaust pipe must be the same diameter as
found in-use for at least 4 pipe diameters upstream to the inlet of the
beginning of the expansion section containing the aftertreatment
device. The exhaust backpressure or restriction shall follow the same
criteria as in Sec. 86.1330-90(f) and may be set with a valve (muffler
omitted). The catalyst container may be removed during all test
sequences prior to the practice cycle, and replaced with an equivalent
container having an inactive catalyst support.
    (i) The engine exhaust systems shall meet the following
requirements:
    (A) The total length of the tubing from the exit of the engine
exhaust manifold, turbocharger outlet or aftertreatment device to the
primary dilution tunnel shall not exceed 32 feet (9.8 m).
    (B) The initial portion of the exhaust system may consist of a
typical in-use (i.e., length, diameter, material, etc.) chassis-type
exhaust system.
    (C) The distance from the exhaust manifold flange(s) or
turbocharger outlet to any exhaust aftertreatment device shall be the
same as in the vehicle configuration or within the distance
specifications provided by the manufacturer.
    (D) For engines which are not equipped with exhaust aftertreatment
devices, all tubing in excess of 12 feet (3.7 m) from the exit of the
turbocharger or exhaust manifold shall be insulated. For engines
equipped with exhaust aftertreatment devices, all tubing after the
aftertreatment device which is in excess of 12 feet (3.7 m) shall be
insulated.
    (E) If the tubing is required to be insulated, the radial thickness
of the insulation must be at least 1.0 inch (25 mm). The thermal
conductivity of the insulating material must have a value no greater
than 0.75 BTU-in/hr/ft2/ deg.F (0.065 W/m-K) measured at 700
 deg.F (371  deg.C).
    (F) A smoke meter or other instrumentation may be inserted into the
exhaust system tubing. If this option is exercised in the insulated
portion of the tubing, then a minimal amount of tubing not to exceed 18
inches may be left uninsulated. However, no more than 12 feet (3.66 m)
of tubing can be left uninsulated in total, including the length at the
smoke meter.
* * * * *
    39. Section 86.1327-98 is added to subpart N to read as follows:

Sec. 86.1327-98  Engine dynamometer test procedures; overview.

    Section 86.1327-98 includes text that specifies requirements that
differ from Sec. 86.1327-96. Where a paragraph in Sec. 86.1327-96 is
identical and applicable to Sec. 86.1327-98, this may be indicated by
specifying the corresponding paragraph and the statement ``[Reserved].
For guidance see Sec. 86.1327-96''.
    (a) through (d)(3) [Reserved]. For guidance see Sec. 86.1327-96.
    (d)(4) Additional accessories (e.g., oil cooler, alternators, air
compressors, etc.) may be installed or their loading simulated if
typical of the in-use application. This loading shall be parasitic in
nature and, if used, shall be applied during all engine testing
operations, including mapping. The accessory work performed shall not
be included in the integrated work used in emissions calculations.
    (d)(5) through (f) [Reserved]. For guidance see Sec. 86.1327-96.
    40. Section 86.1330-84 of subpart N is amended by revising
paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to
read as follows:

Sec. 86.1330-84  Test sequence; general requirements.

* * * * *

[[Page 47131]]

    (b) * * *
    (1) The temperature of the CVS dilution air shall be maintained
above 68  deg.F (20  deg.C) for Otto cycle engines and between 68
deg.F and 86  deg.F (20  deg.C and 30  deg.C) for diesel cycle engines
throughout the test sequence, except as permitted by Sec. 86.1335-84.
    (2) For engines with auxiliary emission control devices which sense
or detect ambient air temperature and operate at 68  deg.F or higher,
the test cell ambient air temperature and the temperature of the engine
intake air shall be maintained at 77  deg.F 9  deg.F (25
deg.C 5  deg.C) throughout the test sequence. For engines
with auxiliary emission control devices which are temperature dependent
and operate at 68  deg.F or higher, the temperature of the engine
intake air shall be maintained at 77  deg.F 9  deg.F (25
deg.C 5  deg.C) throughout the test sequence.
* * * * *
    (5) For engines equipped with an air-to-air intercooler (or any
other low temperature charge air cooling device) between the
turbocharger compressor and the intake manifold, the procedure for
simulating the device in the transient dynamometer test facilities
shall follow the SAE Recommended Practice J1937, ``Engine Testing with
Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
* * * * *
    (f) Diesel-Fueled Engines only. (1)(i) Air inlet restriction shall
be set to a value midway between a clean filter and the maximum
restriction specified by the manufacturer. The exhaust restriction
normally shall be set at 80 percent of the manufacturer's recommended
maximum specified exhaust restriction. The manufacturer shall be liable
for emission compliance from the minimum in-use restrictions to the
maximum restrictions specified by the manufacturer for that particular
engine.
* * * * *
    41. Section 86.1330-90 of subpart N is amended by revising
paragraphs (b)(1), (b)(2), and (f)(1)(i) and adding paragraph (b)(5) to
read as follows:

Sec. 86.1330-90  Test sequence; general requirements.

* * * * *
    (b) * * *
    (1) The temperature of the CVS dilution air shall be maintained at
greater than 68  deg.F (20  deg.C) for Otto cycle engines and between
68  deg.F and 86  deg.F (20  deg.C and 30  deg.C) for diesel cycle
engines throughout the test sequence, except as permitted by
Sec. 86.1335-84.
    (2) For engines with auxiliary emission control devices which sense
or detect ambient air temperature and operate at 68  deg.F or higher,
the test cell ambient air temperature and the temperature of the engine
intake air shall be maintained at 77  deg.F 9  deg.F (25
deg.C 5  deg.C) throughout the test sequence. For engines
with auxiliary emission control devices which are temperature dependent
and operate at 68  deg.F or higher, the temperature of the engine
intake air shall be maintained at 77  deg.F 9  deg.F (25
deg.C 5  deg.C) throughout the test sequence.
* * * * *
    (5) For engines equipped with an air-to-air intercooler (or any
other low temperature charge air cooling device) between the
turbocharger compressor and the intake manifold, the procedure for
simulating the device in the transient dynamometer test facilities
shall follow the SAE Recommended Practice J1937, ``Engine Testing with
Low Temperature Charge Air Cooling System in a Dynamometer Test Cell.''
* * * * *
    (f) Petroleum-fueled and methanol-fueled diesel engines. (1)(i) Air
inlet restriction shall be set to a value midway between a clean filter
and the maximum restriction specified by the manufacturer. The exhaust
restriction normally shall be set at 80 percent of the manufacturer's
recommended maximum specified exhaust restriction. The manufacturer
shall be liable for emission compliance from the minimum in-use
restrictions to the maximum restrictions specified by the manufacturer
for that particular engine.
* * * * *
    42. Section 86.1333-90 of subpart N is amended by revising
paragraphs (c), (d) introductory text, (d)(1), (d)(2), (e)(2) and
removing paragraphs (d)(3) and (d)(4) to read as follows:

Sec. 86.1333-90  Transient test cycle generation.

* * * * *
    (c) Engine speed and torque shall be recorded at least once every
second during the cold start test and hot start test. The torque and
rpm feedback signals may be filtered.
    (d) Idle Speed Enhancement Devices (e.g. cold idle, alternator
idle, etc.). The zero percent speed specified in the engine dynamometer
schedules (appendix I (f)(1), (f)(2), or (f)(3) to this part) shall be
superseded by proper operation of the engine's idle speed enhancement
device.
    (1) During idle speed enhancement device operation, a manual
transmission engine shall be allowed to idle at whatever speed is
required to target a feedback torque equal to zero (using, for example,
clutch disengagement, speed to torque control switching, software
overrides, etc.) at those points in appendix I (f)(1), (f)(2), or
(f)(3) to this part where both reference speed and reference torque are
zero percent values. For each idle segment that is seven seconds or
longer, the average feedback torque must be within 10 ft-
lbs of zero. To allow for transition, up to the first four seconds may
be deleted from each idle segment calculation.
    (2) During idle speed enhancement device operation, an automatic
transmission engine shall be allowed to idle at whatever speed is
required to target a feedback torque equal to CITT (see (e)(2) of this
section for definition of CITT) at those points in appendix I (f)(1),
(f)(2), or (f)(3) to this part where both reference speed and reference
torque are zero percent values. For each idle segment that is seven
seconds or longer, the average feedback torque must be within
10 ft-lbs of CITT. To allow for transition, up to the first
four seconds may be deleted from each idle segment calculation.
    (e) * * *
    (2) All zero-percent speed, zero-percent torque points (idle
points) shall be modified to zero percent speed, Curb Idle Transmission
Torque (CITT), except as permitted in Sec. 86.1337-90(a)(9). Also, all
points with speed equal to or less than zero percent and torque less
than CITT shall be modified to CITT. Motoring torque shall remain
unchanged. In order to provide a smooth torque transition, all
consecutive torque points that are between 0 and CITT shall be changed
to CITT if the first of these is preceded or the last of these is
succeeded by idle points. The manufacturer's specified CITT shall be
based upon that value observed in typical applications at the mean of
the manufacturers' specified idle speed range at stabilized temperature
conditions.
* * * * *
    43. Section 86.1334-84 of subpart N is amended by revising
paragraph (a)(2) to read as follows:

Sec. 86.1334-84  Pre-test engine and dynamometer preparation.

    (a) * * *
    (2) Following any practice runs or calibration procedures, the
engine shall be cooled per Sec. 86.1335-90.
    44. Section 86.1335-90 of subpart N is revised to read as follows:

Sec. 86.1335-90  Cool-down procedure.

    (a) This cool-down procedure applies to Otto-cycle and diesel
engines.
    (b) Engines may be soaked at ambient conditions. No substances or
fluids may

[[Page 47132]]

be applied to the engine's internal or external surfaces except for
water and air as prescribed in paragraphs (c) and (d) of this section.
    (c) For water-cooled engines, two types of cooling are permitted:
    (1) Water may be circulated through the engine's water coolant
system.
    (i) The coolant may be flowed in either direction and at any
desired flow rate. The thermostat may be removed or blocked open during
the cool-down but must be restored before the exhaust emissions test
begins.
    (ii) The temperature of the circulated or injected water shall be
at least 10  deg.C (50  deg.F). In addition, the temperature of the
cooling water shall not exceed 30  deg.C (86  deg.F) during the last 30
minutes of the cool-down.
    (iii) Only water, including the use of a building's standard water
supply, or the coolant type that is already in the engine (per
Sec. 86.1327-90(e)) is permitted for cool-down purposes.
    (2) Flows of air may be directed at the exterior of the engine.
    (i) The air shall be directed essentially uniformly over the
exterior surface of the engine at any desired flow rate.
    (ii) The temperature of the cooling air shall not exceed 86  deg.F
(30  deg.C) during the last 30 minutes of the cool-down, but may be
less than 68  deg.F (20  deg.C) at any time.
    (d) For air-cooled engines, only cooling as prescribed in paragraph
(c)(2) of this section is permitted.
    (e)(1) The cold cycle exhaust emission test may begin after a cool-
down only when the engine oil and water temperatures are stabilized
between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C) for a minimum
of fifteen minutes.
    (i) These temperature measurements are to be made by temperature
measurement devices immersed in the sump oil and in the thermostat
housing or cylinder head cooling circuit, the sensor parts of which are
not in contact with any engine surface.
    (ii) The flow of oil and water shall be shut off during this
measurement. Air flow, except as necessary to keep the cell temperature
between 68  deg.F and 86  deg.F (20  deg.C and 30  deg.C), shall be
shut off. No engine oil change is permitted during the test sequence.
    (2) Direct cooling of engine oil through the use of oil coolers or
heat exchangers is permitted. The cold cycle emission test may begin
only when the requirements in paragraph (e)(1)(ii) are met.
    (3) Any other means for the direct cooling of the engine oil must
be approved in advance by the Administrator.
    (f)(1) The cold cycle exhaust emission test for engines equipped
with exhaust aftertreatment devices may begin after a cool-down only
when the aftertreatment device is 77  deg.F 9  deg.F (25
deg.C 5  deg.C), in addition to the temperature
restrictions in paragraph (e) of this section. For catalysts, this
temperature must be measured at the outlet of the catalyst bed.
    (2) Exhaust aftertreatment device cool-down may be accomplished in
whatever manner and using whatever coolant deemed appropriate by proper
engineering judgment. The aftertreatment device, engine, and exhaust
piping configurations shall not be separated, altered, or moved in any
way during the cool-down.
    (g) For engines with auxiliary emission control devices which are
temperature dependent, the cold start shall not begin until the
temperature readings of the auxiliary emission control devices are
stable at 77  deg.F 9  deg.F (25  deg.C 5
deg.C).
    (h) At the completion of the cool-down all of the general
requirements specified in Sec. 86.1330, the oil temperature
specification set forth in paragraph (e) of this section, and the
catalyst temperature specifications in paragraph (f) of this section
must be met before the cold cycle exhaust emission test may begin.
    45. Section 86.1337-90 of subpart N is amended by revising
paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23),
and (a)(26), and by removing paragraph (a)(10)(iii), to read as
follows:

Sec. 86.1337-90  Engine dynamometer test run.

    (a) * * *
    (9) As soon as it is determined that the engine is started, start a
``free idle'' timer. Allow the engine to idle freely with no-load for
24 1 seconds. This idle period for automatic transmission
engines may be interpreted as an idle speed in neutral or park. All
other idle conditions shall be interpreted as an idle speed in gear. It
is permissible to lug the engine down to curb idle speed during the
last 8 seconds of the free idle period for the purpose of engaging
dynamometer control loops.
    (10) * * *
    (i) During diesel particulate sampling it must be demonstrated that
the ratio of main tunnel flow to particulate sample flow does not
change by more than 5.0 percent of its set point value
(except for the first 10 seconds of sampling).

    Note: For double dilution operation, sample flow is the net
difference between the flow rate through the sample filters and the
secondary dilution air flow rate.

    (ii) Record the average temperature and pressure at the gas
meter(s) or flow instrumentation inlet, where needed to calculate flow.
If the set flow rate cannot be maintained because of high particulate
loading on the filter, the test shall be terminated. The test shall be
rerun using a lower flow rate and/or a larger diameter filter.
    (11) Begin the transient engine cycles such that the first non-idle
record of the cycle occurs at 25 1 seconds. The free idle
time is included in the 25 1 seconds.
* * * * *
    (13) Immediately after the engine is turned off, turn off the
engine cooling fan(s) if used, and the CVS blower (or disconnect the
exhaust system from the CVS). As soon as possible, transfer the ``cold
start cycle'' exhaust and dilution air bag samples to the analytical
system and process the samples according to Sec. 86.1340. A stabilized
reading of the exhaust sample on all analyzers shall be obtained within
20 minutes of the end of the sample collection phase of the test.
Analysis of the methanol and formaldehyde samples shall be obtained
within 24 hours of the end of the sample collection period. For
petroleum-fueled and methanol-fueled diesel engines, carefully remove
the filter holder from the sample flow apparatus, and remove each
particulate sample filter from its holder and invert the secondary
filter and place it stain side to stain side on top of the primary
filter. Place the filter pair in a petri dish and cover.
* * * * *
    (23) Allow the engine to idle freely with no-load for 24
1 seconds. The provisions and interpretations of paragraph
(a)(9) of this section apply.
* * * * *
    (26) As soon as possible, transfer the ``hot start cycle'' exhaust
and dilution air bag samples to the analytical system and process the
samples according to Sec. 86.1340. A stabilized reading of the exhaust
sample on all analyzers shall be obtained within 20 minutes of the end
of the sample collection phase of the test. Analyze the methanol and
formaldehyde samples within 24 hours. (If it is not possible to perform
analysis within 24 hours, the samples should be stored in a cold
(approximately 0 deg.C) dark environment until analysis can be
performed). For petroleum-fueled and methanol-fueled diesel engines,
carefully remove the assembled filter holder from the sample flow lines
and remove each particulate sample filter from its holder and invert
the secondary filter and place it stain side to stain side on top of
the primary filter. Place the filter pairs in a clean petri dish and

[[Page 47133]]

cover as soon as possible. Within 1 hour after the end of the hot start
phase of the test, transfer the particulate filters to the weighing
chamber for post-test conditioning.
* * * * *
    46. Section 86.1337-96 of subpart N is amended by revising
paragraphs (a)(9), (a)(10)(i), (a)(10)(ii), (a)(11), (a)(13), (a)(23),
and (a)(26), and by removing paragraph (a)(10)(iii) to read as follows:

Sec. 86.1337-96  Engine dynamometer test run.

    (a) * * *
    (9) As soon as it is determined that the engine is started, start a
``free idle'' timer. Allow the engine to idle freely with no-load for
241 seconds. This idle period for automatic transmission
engines may be interpreted as an idle speed in neutral or park. All
other idle conditions shall be interpreted as an idle speed in gear. It
is permissible to lug the engine down to curb idle speed during the
last 8 seconds of the free idle period for the purpose of engaging
dynamometer control loops.
    (10) * * *
    (i) During diesel particulate sampling it must be demonstrated that
the ratio of main tunnel flow to particulate sample flow does not
change by more than 5.0 percent of its set point value
(except for the first 10 seconds of sampling). For double dilution
operation, sample flow is the net difference between the flow rate
through the sample filters and the secondary dilution air flow rate.
    (ii) Record the average temperature and pressure at the gas
meter(s) or flow instrumentation inlet, where needed to calculate flow.
If the set flow rate cannot be maintained because of high particulate
loading on the filter, the test shall be terminated. The test shall be
rerun using a lower flow rate and/or a larger diameter filter.
    (11) Begin the transient engine cycles such that the first non-idle
record of the cycle occurs at 251 seconds. The free idle
time is included in the 251 seconds.
* * * * *
    (13) Immediately after the engine is turned off, turn off the
engine cooling fan(s) if used, and the CVS blower (or disconnect the
exhaust system from the CVS). As soon as possible, transfer the ``cold
start cycle'' exhaust and dilution air bag samples to the analytical
system and process the samples according to Sec. 86.1340. A stabilized
reading of the exhaust sample on all analyzers shall be obtained within
20 minutes of the end of the sample collection phase of the test.
Analysis of the methanol and formaldehyde samples shall be obtained
within 24 hours of the end of the sample collection period. For
petroleum-fueled and methanol-fueled diesel engines, carefully remove
the filter holder from the sample flow apparatus, remove each
particulate sample filter from its holder and invert the secondary
filter and place it stain side to stain side on top of the primary
filter. Place the filter pair in a petri dish and cover.
* * * * *
    (23) Allow the engine to idle freely with no-load for
241 seconds. The provisions and interpretations of
paragraph (a)(9) of this section apply.
* * * * *
    (26) As soon as possible, transfer the ``hot start cycle'' exhaust
and dilution air bag samples to the analytical system and process the
samples according to Sec. 86.1340. A stabilized reading of the exhaust
sample on all analyzers shall be obtained within 20 minutes of the end
of the sample collection phase of the test. Analyze the methanol and
formaldehyde samples within 24 hours. (If it is not possible to perform
analysis within 24 hours, the samples should be stored in a cold
(approximately 0  deg.C) dark environment until analysis can be
performed). For petroleum-fueled and methanol-fueled diesel engines,
carefully remove the assembled filter holder from the sample flow lines
and remove each particulate sample filter from its holder and invert
the secondary filter and place it stain side to stain side on top of
the primary filter. Place the filter pairs in a clean petri dish and
cover as soon as possible. Within 1 hour after the end of the hot start
phase of the test, transfer the particulate filters to the weighing
chamber for post-test conditioning.
* * * * *
    47. Section 86.1338-84 of subpart N is revised to read as follows:

Sec. 86.1338-84  Emission measurement accuracy.

    (a) Measurement accuracy--Bag sampling. (1) Good engineering
practice dictates that exhaust emission sample analyzer readings below
15 percent of full scale chart deflection should generally not be used.
    (2) Some high resolution read-out systems such as computers, data
loggers, etc., can provide sufficient accuracy and resolution below 15
percent of full scale. Such systems may be used provided that
additional calibrations of at least 4 non-zero nominally equally spaced
points, using good engineering judgement, below 15 percent of full
scale are made to ensure the accuracy of the calibration curves.
    (3) The following procedure shall be followed:
    (i) Span the analyzer using a calibration gas that meets the
accuracy requirements of Sec. 86.1314-84(f)(2), is within the operating
range of the analyzer and at least 90% of full scale.
    (ii) Generate calibration data over the full concentration range at
a minimum of 6, approximately equally spaced, points (e.g. 15, 30, 45,
60, 75 and 90 percent of the range of concentrations provided by the
gas divider). If a gas divider or blender is being used to calibrate
the analyzer and the requirements of paragraph (a)(2) of this section
are met, verify that a second calibration gas with a concentration
between 10 and 20 percent of full scale can be named within 2 percent
of its certified concentration. If more calibration points are needed
to meet the requirements of paragraph (a)(2) of this section, continue
with paragraph (a)(3)(iii) of this section.
    (iii) If a gas divider or blender is being used to calibrate the
analyzer, input the value of a second calibration gas (a span gas may
be used for calibrating a CO2 analyzer) having a named
concentration between 10 and 20 percent of full scale. This gas shall
be included on the calibration curve. Continue adding calibration
points by dividing this gas until the requirements of paragraph (a)(2)
of this section are met.
    (iv) Fit a calibration curve per Secs. 86.1321 through 86.1324 for
the full scale range of the analyzer using the calibration data
obtained with both calibration gases.
    (b) Measurement accuracy--Continuous sampling. (1) Analyzers used
for continuous analysis must be operated such that the measured
concentration falls between 15 and 100 percent of full scale chart
deflection. Exceptions to these limits are:
    (i) Analyzer response less than 15 percent or more than 100 percent
of full scale may be used if automatic range change circuitry is used
and the limits for range changes are between 15 and 100 percent of full
scale chart deflection;
    (ii) Analyzer response less than 15 percent of full scale may be
used if one of the following is true:
    (A) Alternative (a)(2) of this section is used to ensure that the
accuracy of the calibration curve is maintained below 15 percent; or
    (B) The full scale value of the range is 155 ppm (C) or less.
    (iii) Analyzer response over 100% of full scale may be used if it
can be shown that readings in this range are accurate.
    (iv) The HC and CO readings are allowed to ``spike'' above full
scale of the analyzer's maximum operating range for a maximum
accumulation of 5

[[Page 47134]]

seconds. These analyzer readings shall default to the maximum readable
value during this time.
    (c) If a gas divider is used, the gas divider shall conform to the
accuracy requirements specified in Sec. 86.1314-84(g), and shall be
used according to the procedures contained in (a) and (b) of this
section.
    48. Section 86.1339-90 of subpart N is revised to read as follows:

Sec. 86.1339-90  Particulate filter handling and weighing.

    (a) At least 1 hour before the test, place a filter pair in a
closed (to eliminate dust contamination) but unsealed (to permit
humidity exchange) petri dish and place in a weighing chamber meeting
the specifications of Sec. 86.1312 for stabilization.
    (b) At the end of the stabilization period, weigh each filter pair
on a balance having a precision of 20 micrograms and a readability of
10 micrograms. This reading is the tare weight of the filter pair and
must be recorded (see Sec. 86.1344(e)(18)).
    (c) The filter pair shall then be stored in a covered petri dish or
a sealed filter holder, either of which shall remain in the weighing
chamber until needed for testing.
    (d) If the filter pair is not used within 1 hour of its removal
from the weighing chamber, it must be re-weighed before use. This limit
of 1 hour may be replaced by an 8-hour limit if either of the following
three conditions are met:
    (1) A stabilized filter pair is placed and kept in a sealed filter
holder assembly with the ends plugged; or
    (2) A stabilized filter pair is placed in a sealed filter holder
assembly, which is then immediately placed in a sample line through
which there is no flow; or
    (3) A combination of the conditions specified in paragraphs (d) (1)
and (2) of this section.
    (e) After the emissions test, remove the filters from the filter
holder and place them face to face in a covered but unsealed petri
dish. They must then be conditioned in the weighing chamber for at
least one hour. The filters are then weighed as a pair. This reading is
the gross weight of the filters (Pf) and must be recorded (see
Sec. 86.1344-90(e)(19)).
    (f) The net particulate weight (Pf) on each filter pair is the
gross weight minus the tare weight. Should the sample on the filters
(exhaust or background) contact the petri dish or any other surface,
the test is void and must be rerun.
    (g) Static neutralizers shall be used on petri dishes in accordance
with good engineering judgement.
    49. Section 86.1341-90 of subpart N is amended by revising
paragraphs (b), (c) and (d) and removing paragraphs (e) through (h) to
read as follows:

Sec. 86.1341-90  Test cycle validation criteria.

    (a) * * *
    (b) Brake horsepower-hour calculation. (1) Calculate the brake
horsepower-hour for each pair of engine feedback speed and torque
values recorded. Also calculate the reference brake horsepower-hour for
each pair of engine speed and torque reference values. Calculations
shall be to five significant digits.
    (2) In integrating the reference and the feedback horsepower-hour,
all negative torque values shall be set equal to zero and included. If
integration is performed at a frequency of less than 5 Hz, and if
during a given time segment, the torque value changes from positive to
negative or negative to positive, then the negative portion must be
computed by linear interpolation and set equal to zero and the positive
portion included. The same methodology shall be used for integrating
both reference and actual brake horsepower-hour.
    (c) Regression line analysis to calculate validation statistics.
(1) Linear regressions of feedback value on reference value shall be
performed for speed, torque and brake horsepower on 1 Hz data after the
feedback shift has occurred (see paragraph (a) of this section). The
method of least squares shall be used, with the best fit equation
having the form:

y=mx+b

Where:

y = The feedback (actual) value of speed (rpm), torque (ft-lbs), or
brake horsepower.
m = Slope of the regression line.
x = The reference value (speed, torque, or brake horsepower).
b = The y-intercept of the regression line.

    (2) The standard error of estimate (SE) of y on x and the
coefficient of determination (r2) shall be calculated for
each regression line.
    (3) For a test to be considered valid, the criteria in Figure N90-
11 must be met for both cold and hot cycles individually. Point
deletions from the regression analyses are permitted where noted in
Figure N90-11.

                                                                      Figure N90-11
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Speed                                    Torque                          BHP
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Regression Line Tolerances

                                                   Petroleum-fueled and methanol-fueled diesel engines
Standard error of estimate (SE) of Y    100 rpm...........................................  13 pct. of power map maximum   8 pct. of power map maximum
 on X.                                                                                       engine torque                  BHP.
Slope of the regression line, m.......  0.970 to 1.030....................................  0.83-1.03 (hot), 0.77-1.03     0.89-1.03 (hot), 0.87-1.03
                                                                                             (cold)                         (cold).
Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.8800 (hot), \1\ 0.8500   \1\ 0.9100.
                                                                                             (cold).
Y intercept of the regression line, b.  50 rpm................................  15 ft-lb.........  5.0 BHP.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Gasoline-fueled and methanol-fueled Otto-cycle engines
--------------------------------------------------------------------------------------------------------------------------------------------------------
Standard error of estimate (SE) of Y    100 rpm...........................................  10% (hot), 11% (cold) of       5% (hot), 6% (cold) of power
 on X.                                                                                       power map max. engine torque.  map maximum BHP.
Slope of the regression line, m.......  0.980 to 1.020....................................  0.92-1.03 (hot), 0.88-1.03     0.93-1.03 (hot), 0.89-1.03
                                                                                             (cold)                         (cold).
Coefficient of determination, r \2\...  \1\ 0.9700........................................  \1\ 0.9300 (hot), \1\ 0.9000   \1\ 0.9400 (hot), \1\ 0.9300
                                                                                             (cold)                         (cold).
Y intercept of the regression line, b.  25 (hot), 40 (cold).......  4% (hot), plus-minus>2.0% (hot), 5 (cold) of power map    minus>2.5% (cold) of power
                                                                                             max. engine torque.            map BHP.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Minimum.

[[Page 47135]]

           Permitted Point Deletions From Regression Analysis
------------------------------------------------------------------------
                 Condition                      Points to be deleted
------------------------------------------------------------------------
1. Wide Open Throttle and Torque Feedback   Torque, and/or BHP.
  Torque Reference.
3. Closed Throttle, Idle Point, and Torque  Speed, and/or BHP.
 Feedback = CITT (10 ft-lb).

  For the purposes of this discussion:

  An Idle Point is defined as a point having a Normalized Reference
Torque of 0 and a Normalized Reference Speed of 0 and an engine tested
as having a manual transmission has a CITT of 0. Point deletion may be
applied either to the whole or to any part of the cycle.
------------------------------------------------------------------------

    (4)(i) For petroleum-fueled and methanol-fueled diesel engines, the
integrated brake horsepower-hour for each cycle (cold and hot start)
shall be between -15 percent and +5 percent of the integrated brake
horsepower-hour for the reference cycle, or the test is void.
    (ii) For gasoline-fueled and methanol-fueled Otto-cycle engines,
the integrated brake horsepower-hour of the feedback cycle shall be
within 5 percent of the integrated brake horsepower-hour of the
reference cycle for the cold cycle, or the test is void. The tolerance
for the hot cycle shall be 4 percent.
    (5) If a dynamometer test run is determined to be statistically or
experimentally void, corrective action shall be taken. The engine shall
then be allowed to cool (naturally or forced) and the dynamometer test
rerun per Sec. 86.1337 or be restarted at Sec. 86.1336-84(e).
    (d) For petroleum-fueled and methanol-fueled diesel engines, all
reference torque values specified (in paragraph (f)(2) of appendix I to
this part) as ``closed throttle'' shall be deleted from the calculation
of cycle torque and power validation statistics.
    50. Section 86.1341-98 is added to subpart N and reads as follows:

Sec. 86.1341-98  Test cycle validation criteria.

    Section 86.1341-98 includes text that specifies requirements that
differ from Sec. 86.1341-90. Where a paragraph in Sec. 86.1341-90 is
identical and applicable to Sec. 86.1341-98, this may be indicated by
specifying the corresponding paragraph and the statement ``[Reserved].
For guidance see Sec. 86.1341-90''
    (a) Through (b)(2) [Reserved]. For guidance see Sec. 86.1341-90.
    (b)(3) All feedback torques due to accessory loads, either actual
or simulated as defined in Sec. 86.1327-90 (d)(4), shall be excluded
from both cycle validation and the integrated work used for emissions
calculations.
    (4) For reference idle portions of the cycle where CITT is not
applied, use measured torque values for cycle validation and the
reference torque values for calculating the brake horsepower-hour value
used in the emission calculations. For reference idle portions of the
cycle where CITT is applied, use measured torque values for cycle
validation and calculating the brake horsepower-hour value used in the
emission calculations.
    (c) Through (d) [Reserved]. For guidance see Sec. 86.1341-90.
    51. Section 86.1342-90 of subpart N is amended by removing
paragraphs (h)(2)(i), (h)(2)(ii), (h)(2)(iii), (h)(2)(iv), (h)(2)(v),
(h)(2)(vi), (h)(2)(vii) and adding paragraph (i) to read as follows:

Sec. 86.1342-90  Calculations; exhaust emissions.

* * * * *
    (i) For dilute sampling systems which require conversion of as-
measured dry concentrations to wet concentrations, the following
equation shall be used for any combination of bagged, continuous, or
fuel mass-approximated sample measurements (except for CO measurements
made through conditioning columns, as explained in paragraph (d)(3) of
this section):

Wet concentration = Kw  x  dry concentration.

Where:

    (1)(i) For English units,

Kw = 1-(/200)  x  CO2e(')-((1.608  x
H)/(7000 + 1.608  x  H))

    See paragraph (d)(1) of this section for  values.
    (ii) For SI units,

Kw = 1-(/200)  x  CO2e(')-((1.608  x
H)/(1000 + 1.608  x  H))

    See paragraph (d)(1) of this section for  values.

(2) CO2e(') = either CO2e or CO2e' as
applicable.
(3)(i) H = Absolute humidity of the CVS dilution air, in grains (grams)
of water per lb (kg) of dry air.

    (ii) For English units,

H ' = [(43.478)Ri'  x  Pd']/
[PB-(Pd'  x  Ri'/100)]

    (iii) For SI units,

H' = [(6.211)Ri'  x  Pd']/
[PB-(Pd'  x  Ri'/100)]
(4) Ri = Relative humidity of the CVS dilution air, in
percent.
(5) Pd = Saturated vapor pressure, in mm Hg (kPa) at the
ambient dry bulb temperature of the CVS dilution air.
(6) PB = Barometric pressure, mm Hg (kPa).

    52. Section 86.1342-94 is amended by revising paragraphs (e)
through (h) and adding paragraph (i) to read as follows:

Sec. 86.1342-94  Calculations; exhaust emissions.

* * * * *
    (e) Through (i) [Reserved]. For guidance see Sec. 86.1342-90.
    53. Section 86.1343-88 is amended by revising the introductory text
of paragraph (b), redesignating paragraphs (b)(2)(i) through (b)(2)(v)
as paragraphs (b)(2)(ii) through (b)(2)(vi) respectively and by adding
a new paragraph (b)(2)(i) to read as follows:

Sec. 86.1343-88  Calculations; particulate exhaust emissions.

* * * * *
    (b) The mass of particulate for the cold-start test and the hot-
start test is determined from the following equation:
* * * * *
    (2)(i)(A) For a CFV-CVS: Vmix = Total dilute exhaust
volume corrected to standard conditions (293  deg.K (20  deg.C) and
101.3 kPa (760 mm Hg)), cubic feet per test phase.
    (B) For a PDP-CVS:
    [GRAPHIC] [TIFF OMITTED] TR05SE97.006

in SI units,
[GRAPHIC] [TIFF OMITTED] TR05SE97.007

Where:
* * * * *
    \1\ Closed throttle motoring.
---------------------------------------------------------------------------

    \1\

---------------------------------------------------------------------------

[[Page 47136]]

    53. Appendix I to part 86 is amended by revising the footnote to
the table in paragraph (f)(2) to read as follows:

Appendix I to Part 86--Urban Dynamometer Schedules

* * * * *
    (f)(1) * * *
    (2) * * *

* * * * *
[FR Doc. 97-23352 Filed 9-4-97; 8:45 am]
BILLING CODE 6560-50-P



 
 


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