[Code of Federal Regulations]
[Title 40, Volume 17]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR86.091-28]
[Page 158-164]
TITLE 40--PROTECTION OF ENVIRONMENT
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
PART 86_CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND
ENGINES--Table of Contents
Subpart A_General Provisions for Emission Regulations for 1977 and Later
Sec. 86.091-28 Compliance with emission standards.
(a)(1) Paragraph (a) of this section applies to light-duty vehicles.
(2) The applicable exhaust and fuel evaporative emissions standards
(and family particulate emission limits, as appropriate) of this subpart
apply to the emissions of vehicles for their useful life.
(3) Since it is expected that emission control efficiency will
change with mileage accumulation on the vehicle, the emission level of a
vehicle which has accumulated 50,000 miles will be used as the basis for
determining compliance with the standards (or family particulate
emission limit, as appropriate).
(4) The procedure for determining compliance of a new motor vehicle
with exhaust emission standards (or family particulate emission limit,
as appropriate) is as follows, except where specified by paragraph
(a)(7) of this section for the Alternative Durability Program:
(i) Separate emission deterioration factors shall be determined from
the exhaust emission results of the durability-data vehicle(s) for each
engine-system combination. A separate factor shall be established, as
required for compliance with applicable emission standards for exhaust
HC, exhaust THCE, exhaust NMHC, exhaust CO, exhaust NOX and
exhaust particulate for each engine-system combination. A separate
evaporative emission deterioration factor, as required for compliance
with applicable emission standards, shall be determined for each
evaporative emission family-evaporative emission control system
combination from the testing conducted by the manufacturer.
(A) The applicable results to be used unless excluded by paragraph
[[Page 159]]
(a)(4)(i)(A)(4) of this section in determining the exhaust emission
deterioration factors for each engine-system combination shall be:
(1) All valid exhaust emission data from the tests required under
Sec. 86.084-26(a)(4) except the zero-mile tests. This shall include the
official test results, as determined in Sec. 86.091-29 for all tests
conducted on all durability-data vehicles of the combination selected
under Sec. 86.085-24(c) (including all vehicles elected to be operated
by the manufacturer under Sec. 86.085-24(c)(1)(ii)).
(2) All exhaust emission data from the tests conducted before and
after the scheduled maintenance provided in Sec. 86.088-25.
(3) All exhaust emission data from tests required by maintenance
approved under Sec. 86.088-25, in those cases where the Administrator
conditioned his approval for the performance of such maintenance on the
inclusion of such data in the deterioration factor calculation.
(4) The manufacturer has the option of applying an outlier test
point procedure to completed durability data within its certification
testing program for a given model year. The outlier procedure will be
specified by the Administrator. For any pollutant, durability-data test
points that are identified as outliers shall not be included in the
determination of deterioration factors if the manufacturer has elected
this option. The manufacturer shall specify to the Administrator before
the certification of the first engine family for that model year, if it
intends to use the outlier procedure. The manufacturer may not change
procedures after the first engine family of the model year is certified.
Where the manufacturer chooses to apply both the outlier procedure and
averaging (as allowed under Sec. 86.084-26(a)(6)(i)) to the same data
set, the outlier procedure shall be completed prior to applying the
averaging procedure.
(B) All applicable exhaust emission results shall be plotted as a
function of the mileage on the system, rounded to the nearest mile, and
the best fit straight lines, fitted by the method of least squares,
shall be drawn through all these data points. The data will be
acceptable for use in the calculation of the deterioration factor only
if the interpolated 4,000-mile and 50,000-mile points on this line are
within the low-altitude standards provided in Sec. 86.087-8. Exceptions
to this where data are still acceptable are when a best fit straight
line crosses an applicable standard but no data points exceeded the
standard, or the best fit straight line crosses an applicable standard
with a negative slope (the 4,000-mile interpolated point is higher than
the 50,000-mile interpolated point) but the 50,000-mile actual data
point is below the standard. An multiplicative exhaust emission
deterioration factor shall be calculated for each engine-system
combination as follows:
Factor=Exhaust emissions interpolated to 50,000 miles divided by exhaust
emissions interpolated to 4,000 miles.
These interpolated values shall be carried out to a minimum of four
places to the right of the decimal point before dividing one by the
other to determine the deterioration factor. The results shall be
rounded to three places to the right of the decimal point in accordance
with ASTM E 29-67.
(C)(1) An evaporative emissions deterioration factor shall be
determined from the testing conducted as described in Sec. 86.090-
21(b)(4)(i), for each evaporative emission family- evaporative emission
control system combination to indicate the evaporative emission level at
50,000 miles relative to the evaporative emission level at 4,000 miles
as follows:
Factor = Evaporative emission level at 50,000 miles minus the
evaporative emission level at 4,000 miles.
(2) The factor in paragraph (a)(4)(i)(C)(1) of this section shall be
established to a minimum of two places to the right of the decimal.
(ii)(A) The official exhaust emission test results for each
emission-data vehicle at the selected test point shall be multiplied by
the appropriate deterioration factor: Provided, that if a deterioration
factor as computed in paragraph (a)(4)(i)(B) of this section is less
than one, that deterioration factor shall be one for the purposes of
this paragraph.
[[Page 160]]
(B) The official evaporative emission test results for each
evaporative emission-data vehicle at the selected test point shall be
adjusted by addition of the appropriate deterioration factor: Provided,
that if a deterioration factor as computed in paragraph (a)(4)(i)(C) of
this section is less than zero, that deterioration factor shall be zero
for the purposes of this paragraph.
(iii) The emissions to compare with the standard (or the family
particulate emission limit, as appropriate) shall be the adjusted
emissions of paragraphs (a)(4)(ii) (A) and (B) of this section for each
emission-data vehicle. Before any emission value is compared with the
standard (or the family particulate emission limit, as appropriate), it
shall be rounded, in accordance with ASTM E 29-67, to two significant
figures. The rounded emission values may not exceed the standard (or the
family particulate emission limit, as appropriate).
(iv) Every test vehicle of an engine family must comply with the
exhaust emission standards (or the family particulate emission limit, as
appropriate), as determined in paragraph (a)(4)(iii) of this section,
before any vehicle in that family may be certified.
(v) Every test vehicle of an evaporative emission family must comply
with the evaporative emission standard, as determined in paragraph
(a)(4)(iii) of this section, before any vehicle in that family may be
certified.
(5) If a manufacturer chooses to change the level of any family
particulate emission limit(s) in the particulate averaging program,
compliance with the new limit(s) must be based upon existing
certification data.
(6) If a manufacturer chooses to participate in the diesel
particulate averaging program, the production-weighted average of the
family particulate emission limits of all affected engine families must
comply with the particulate standards in Sec. 86.087-8(a)(1)(iv), or
the composite particulate standard defined in Sec. 86.085-2, as
appropriate, at the end of the production year.
(7) The procedure to determine the compliance of new motor vehicles
in the Alternative Durability Program (described in Sec. 86.085-13) is
the same as described in paragraphs (a)(4)(iii) through (a)(4)(v) of
this section. For the engine families that are included in the
Alternative Durability Program, the exhaust emission deterioration
factors used to determine compliance shall be those that the
Administrator has approved under Sec. 86.085-13(c). The evaporative
emission deterioration factor for each evaporative emission family shall
be determined and applied according to paragraph (a)(4) of this section.
The procedures to determine the minimum exhaust emissions deterioration
factors required under Sec. 86.085-13(d) are as follows:
(i) Separate deterioration factors shall be determined from the
exhaust emission results of the durability-data vehicles for each engine
family group. A separate factor as necessary to establish compliance
with applicable emission standards shall be established for exhaust HC,
exhaust THCE, exhaust NMHC, exhaust CO and exhaust NOX for
each engine family group. The evaporative emission deterioration factor
for each evaporative family will be determined and applied in accordance
with paragraph (a)(4) of this section.
(ii) The deterioration factors for each engine family group shall be
determined by the Administrator using historical durability data from as
many as three previous model years. These data will consist of
deterioration factors generated by durability-data vehicles representing
certified engine families and of deterioration factors from vehicles
selected under Sec. 86.085-24(h). The Administrator shall determine how
these data will be combined for each engine family group.
(A) The test result to be used in the calculation of each
deterioration factor to be combined for each engine family group shall
be those test results specified in paragraph (a)(4)(i)(A) of this
section.
(B) For each durability-data vehicles selected under Sec. 86.085-
24(h), all applicable exhaust emissions results shall be plotted as a
function of the mileage on the system rounded to the nearest mile, and
the best fit straight lines, fitted by method of least squares, shall be
drawn through all these data points. The exhaust deterioration factor
for each durability-data vehicles shall be calculated as specified in
paragraph (a)(4)(i)(B) of this section.
[[Page 161]]
(C) Line-crossing. For the purposes of paragraph (a)(5) of this
section, line crossing occurs when either of the interpolated 4,000- and
50,000-mile points of the best fit straight line exceeds the applicable
emission standard and at least one applicable data point exceeds the
standard.
(1) The Administrator will not accept for certification line-
crossing data from preproduction durability-data vehicles selected under
Sec. 86.085-24(c), Sec. 86.085-24(h)(2), or (h)(3).
(2) The Administrator will not accept for certification line-
crossing data from production durability-data vehicles selected under
Sec. 86.085-24(h)(1) unless the 4,000-mile test result multiplied by
the engine family group deterioration factor does not exceed the
applicable emission standards. The deterioration factors used for this
purpose shall be those that were used in the certification of the
production vehicle. Manufacturers may calculate this product immediately
after the 4,000-mile test of the vehicle. If the product exceeds the
applicable standards, the manufacturer may, with the approval of the
Administrator, discontinue the vehicle and substitute a new vehicle. The
manufacturer may continue the original vehicle, but the data will not be
acceptable if line crossing occurs.
(b)(1) Paragraph (b) of this section applies to light-duty trucks.
(2) The exhaust and evaporative emission standards (and family
emission limits, as appropriate) of Sec. 86.091-9 apply to the
emissions of vehicles for their useful life.
(3) Since emission control efficiency generally decreases with the
accumulation of mileage on the vehicle, deterioration factors will be
used in combination with emission-data vehicle test results as the basis
for determining compliance with the standards (or family emission
limits, as appropriate).
(4)(i) Paragraph (b)(4) of this section describes the procedure for
determining compliance of a new vehicle with exhaust emission standards
(or family emission limits, as appropriate), based on deterioration
factors supplied by the manufacturers, except where specified by
paragraph (b)(5) of this section for the Alternative Durability Program.
(ii) Separate exhaust emission deterioration factors, determined
from tests of vehicles, engines, subsystems or components conducted by
the manufacturer, shall be supplied for each engine-system combination.
Separate factors shall be established as required for compliance with
applicable emission standards for transient HC, THCE, NMHC, CO, and
NOX, idle CO and exhaust particulate.
(iii) For transient HC, THCE, NMHC and CO, and NOX, idle
CO and/or exhaust particulate as appropriate, the official exhaust
emission results for each emission-data vehicle at the selected test
point shall be adjusted by multiplication by the appropriate
deterioration factor. However, if the deterioration factor supplied by
the manufacturer is less than one, it shall be one for the purposes of
this paragraph.
(iv) The emission values to compare with the standards (or family
emission limits, as appropriate) shall be the adjusted emission values
of paragraph (b)(4)(iii) of this section rounded to two significant
figures in accordance with ASTM E 29-67 for each emission-data engine.
(5)(i) Paragraph (b)(5)(i) of this section applies only to
manufacturers electing to participate in the particulate averaging
program.
(A) If a manufacturer chooses to change the level of any family
particulate emission limit(s), compliance with the new limit(s) must be
based upon existing certification data.
(B) The production-weighted average of the family particulate
emission limits of all applicable engine families, rounded to two
significant figures in accordance with ASTM E 29-67, must comply with
the particulate standards in Sec. 86.088-9 (a)(1)(iv) or (d)(1)(iv), or
the composite particulate standard as defined in Sec. 86.085-2, as
appropriate, at the end of the product year.
(ii) Paragraph (b)(5)(ii) of this section applies only to
manufacturers electing to participate in the NOX averaging
program.
(A) If a manufacturer chooses to change the level of any family
NOX emission limit(s), compliance with the new limit(s) must
be based upon existing certification data.
[[Page 162]]
(B) The production-weighted average of the family NOX
emission limits of all applicable engine families, rounded to two
significant figures in accordance with ASTM E 29-67, must comply with
the NOX emission standards of Sec. 86.088-9(a)(1)(iii) (A)
or (B), or of Sec. 86.088-9(d)(1)(iii) (A) or (B), or the composite
NOX standard as defined in Sec. 86.088-2, at the end of the
product year.
(6) The procedure to determine the compliance of new motor vehicles
in the Alternative Durability Program (described in Sec. 86.085-13) is
the same as described in paragraph (b)(4)(iv), (b)(7)(iv) and (b)(8) of
this section. For the engine families that are included in the
Alternative Durability Program, the exhause emission deterioration
factors used to determine compliance shall be those that the
Administrator has approved under Sec. 86.085-13(c). The evaporative
emission deterioration factor for each evaporative emission family shall
be determined and applied according to paragraph (b)(7) of this section.
The procedures to determine the minimum exhaust emissions deterioration
factors required under Sec. 86.085-13(d) are as follows:
(i) Separate deterioration factors shall be determined from the
exhaust emission results of the durability-data vehicles for each engine
family group. A separate factor shall be established for exhaust HC,
exhaust THCE or exhaust NMHC as appropriate, and exhaust CO and exhaust
NOX for each engine family group. The evaporative emission
deterioration factor for each evaporative family will be determined and
applied in accordance with paragraph (b)(6) of this section.
(ii) The deterioration factors for each engine family group shall be
determined by the Administrator using historical durability data from as
many as three previous model years. These data will consist of
deterioration factors generated by durability-data vehicles representing
certified engine families and of deterioration factors from vehicles
selected under Sec. 86.085-24(h). The Administrator shall determine how
these data will be combined for each engine family group.
(A) The test results to be used in the calculations of each
deterioration factor to be combined for each engine family group shall
be those test results specified in paragraph (a)(4)(i)(A) of this
section.
(B) For each durability-data vehicle selected under Sec. 86.085-
24(h), all applicable exhaust emission results shall be plotted as a
function of the mileage on the system rounded to the nearest mile, and
the best fit straight lines, fitted by the method of least squares,
shall be drawn through all these data points. The exhaust deterioration
factor for each durability-data vehicle shall be calculated as specified
in paragraph (a)(4)(i)(B) of this section.
(C) Line crossing. For the purposes of paragraph (b)(5) of this
section, line crossing occurs when either of the interpolated 4,000- and
120,000-mile points of the best fit straight line exceeds the applicable
emission standard and at least one applicable data point exceeds the
standard.
(1) The Administrator will not accept for certification line-
crossing data from preproduction durability-data vehicles selected under
Sec. 86.085-24(c)(1), or Sec. 86.085-24 (h)(2) or (h)(3).
(2) The Administrator will not accept for certification line-
crossing data from production durability-data vehicles selected under
Sec. 86.085-24(h)(1) unless the 4,000-mile test result multiplied by
the engine family group deterioration factor does not exceed the
applicable emission standard. The deterioration factors used for this
purpose shall be those that were used in the certification of the
production vehicle. Manufacturers may calculate this product immediately
after the 4,000-mile test of the vehicle. If the product exceeds the
applicable standard, the manufacturer may, with the approval of the
Administrator, discontinue the vehicle and substitute a new vehicle. The
manufacturer may continue the original vehicle, but the data will not be
acceptable if line crossing occurs.
(7)(i) Paragraph (b)(7) of this section describes the procedure for
determining compliance of a new vehicle with fuel evaporative emission
standards. The procedure described here shall be used for all vehicles
in all model years.
(ii) The manufacturer shall determine, based on testing described in
[[Page 163]]
Sec. 86.091-21(b)(4)(i), and supply an evaporative emission
deterioration factor for each evaporative emission family-evaporative
emission control system combination. The factor shall be calculated by
subtracting the emission level at the selected test point from the
emission level at the useful life point.
(iii) The official evaporative emission test results for each
evaporative emission-data vehicle at the selected test point shall be
adjusted by the addition of the appropriate deterioration factor.
However, if the deterioration factor supplied by the manufacturer is
less than zero, it shall be zero for the purposes of this paragraph.
(iv) The emission value to compare with the standards shall be the
adjusted emission value of paragraph (b)(7)(iii) of this section rounded
to two significant figures in accordance with ASTM E 29-67 for each
evaporative emission-data vehicle.
(8) Every test vehicle of an engine family must comply with all
applicable standards (and family emission limits, as appropriate), as
determined in paragraphs (b)(4)(iv) and (b)(7)(iv) of this section,
before any vehicle in that family will be certified.
(c)(1) Paragraph (c) of this section applies to heavy-duty engines.
(2) The exhaust emission standards (or family emission limits, as
appropriate) for Otto-cycle engines in Sec. 86.090-10 or for diesel
engines in Sec. 86.091-11 apply to the emissions of engines for their
useful life.
(3) Since emission control efficiency generally decreases with the
accumulation of service on the engine, deterioration factors will be
used in combination with emission-data engine test results as the basis
for determining compliance with the standards.
(4)(i) Paragraph (c)(4) of this section describes the procedure for
determining compliance of an engine with emission standards (or family
emission limits, as appropriate), based on deterioration factors
supplied by the manufacturer.
(ii) Separate exhaust emission deterioration factors, determined
from tests of engines, subsystems or components conducted by the
manufacturer, shall be supplied for each engine-system combination. For
Otto-cycle engines, separate factors shall be established for transient
HC, THCE or NMHC as appropriate, CO and NOX; and idle CO, for
those engines utilizing aftertreatment technology (e.g., catalytic
converters). For diesel engines, separate factors shall be established
for transient HC, THCE or NMHC as appropriate, CO, NOX and
exhaust particulate. For diesel smoke testing, separate factors shall
also be established for the acceleration mode (designated as ``A''), the
lugging mode (designated as ``B''), and peak opacity (designated as
``C'').
(iii)(A) Paragraph (c)(4)(iii)(A) of this section applies to Otto-
cycle heavy-duty engines.
(1) Otto-cycle heavy-duty engines not utilizing aftertreatment
technology (e.g., catalytic converters). For transient HC, THCE or NMHC
as appropriate, CO and NOX, the official exhaust emission
results for each emission-data engine at the selected test point shall
be adjusted by the addition of the appropriate deterioration factor.
However, if the deterioration factor supplied by the manufacturer is
less than zero, it shall be zero for the purposes of this paragraph.
(2) Otto-cycle heavy-duty engines utilizing aftertreatment
technology (e.g., catalytic converters). For transient HC, THCE or NMHC
as appropriate, CO and NOX, and for idle CO, the official
exhaust emission results for each emission-data engine at the selected
test point shall be adjusted by multiplication by the appropriate
deterioration factor. However, if the deterioration factor supplied by
the manufacturer is less than one, it shall be one for the purposes of
this paragraph.
(B) Paragraph (c)(4)(iii)(B) of this section applies to diesel
heavy-duty engines.
(1) Diesel heavy-duty engines not utilizing aftertreatment
technology (e.g., particulate traps). For transient HC, THCE or NMHC as
appropriate, CO, NOX and exhaust particulate, the official
exhaust emission results for each emission-data engine at the selected
test point shall be adjusted by the addition of the appropriate
deterioration factor. However, if the deterioration factor supplied by
the manufacturer is less than zero, it shall be zero for the purposes of
this paragraph.
[[Page 164]]
(2) Diesel heavy-duty engines utilizing aftertreatment technology
(e.g., particulate traps). For transient HC, THCE or NMHC as
appropriate, CO, NOX and exhaust particulate, the official
exhaust emission results for each emission-data engine at the selected
test point shall be adjusted by multiplication by the appropriate
deterioration factor. However, if the deterioration factor supplied by
the manufacturer is less than one, it shall be one for the purposes of
this paragraph.
(3) Diesel heavy-duty engines only. For acceleration smoke (``A''),
lugging smoke (``B''), and peak smoke (``C''), the official exhaust
emission results for each emission-data engine at the selected test
point shall be adjusted by the addition of the appropriate deterioration
factor. However, if the deterioration factor supplied by the
manufacturer is less than zero, it shall be zero for the purposes of
this paragraph.
(iv) The emission values to compare with the standards (or family
emission limits, as appropriate) shall be the adjusted emission values
of paragraph (c)(4)(iii) of this section, rounded to the same number of
significant figures as contained in the applicable standard in
accordance with ASTM E 29-67, for each emission-data engine.
(5)-(6) [Reserved]
(7) Every test engine of an engine family must comply with all
applicable standards (or family emission limits, as appropriate), as
determined in paragraph (c)(4)(iv) of this section, before any engine in
that family will be certified.
(d)(1) Paragraph (d) of this section applies to heavy-duty vehicles
required to comply with evaporative emission standards.
(2) The applicable evaporative emission standard in Sec. 86.091-10
or Sec. 86.091-11 applies to the emissions of vehicles for their useful
life.
(3)(i) For vehicles with a GVWR of up to 26,000 pounds, because it
is expected that emission control efficiency will change during the
useful life of the vehicle, an evaporative emission deterioration factor
shall be determined from the testing described in Sec. 86.088-23(b)(3)
for each evaporative emission family-evaporative emission control system
combination to indicate the evaporative emission control system
deterioration during the useful life of the vehicle (minimum 50,000
miles). The factor shall be established to a minimum of two places to
the right of the decimal.
(ii) For vehicles with a GVWR of greater than 26,000 pounds, because
it is expected that emission control efficiency will change during the
useful life of the vehicle, each manufacturer's statement as required in
Sec. 86.088-23(b)(4)(ii) shall include, in accordance with good
engineering practice, consideration of control system deterioration.
(4) The evaporative emission test results, if any, shall be adjusted
by the addition of the appropriate deterioration factor: Provided, That
if the deterioration factor as computed in paragraph (d)(3) of this
section is less than zero, that deterioration factor shall be zero for
the purposes of this paragraph.
(5) The emission level to compare with the standard shall be the
adjusted emission level of paragraph (d)(4) of this section. Before any
emission value is compared with the standard, it shall be rounded, in
accordance with ASTM E 29-67, to two significant figures. The rounded
emission values may not exceed the standard.
(6) Every test vehicle of an evaporative emission family must comply
with the evaporative emission standard, as determined in paragraph
(d)(5) of this section, before any vehicle in that family may be
certified.
(e) Unless a manufacturer develops specific cold temperature
deterioration factors, 68-86 [deg]F deterioration factors shall be used
to determine compliance with cold temperature emission standards.
(Secs. 202, 203, 206, 207, 208, 301a, Clean Air Act, as amended; 42
U.S.C. 7521, 7522, 7525, 7541, 7542, 7601a)
[50 FR 10669, Mar. 15, 1985, as amended at 51 FR 24609, July 7, 1986; 54
FR 14484, Apr. 11, 1989; 57 FR 31897, July 17, 1992; 59 FR 48493, Sept.
21, 1994]