[Code of Federal Regulations]
[Title 40, Volume 27]
[Revised as ofJuly 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR610.31]

[Page 939-940]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 610--FUEL ECONOMY RETROFIT DEVICES--Table of Contents
 
                  Subpart C--Test Requirement Criteria
 
Sec. 610.31  Vehicle tests for fuel economy and exhaust emissions.

    (a) The tests described in subpart D, E, or F may be conducted if 
existing

[[Page 940]]

data or other information are insufficient to support claims for a 
device in any of these areas:
    (1) Degree of improvement in fuel economy
    (2) Effect on exhaust emissions
    (3) Vehicle applicability
    (b) The Administrator may determine that, in certain cases, tests 
using engine dynamometers are adequate for determining the effect of a 
device. Examples of such cases are given below.
    (1) Long-term effects. In some cases, it may be necessary for the 
engine to operate for several thousand miles before the effectiveness 
can be adequately measured. In such cases an engine dynamometer will 
permit a less expensive and better controlled durability and economy 
test than one in which a vehicle must be driven on a durability route 
and then tested on a chassis dynamometer or test track.
    (2) Durability requirements. Aspects of engine durability can be 
efficiently determined using specialized engine testing rather than 
through durability mileage accumulation in a vehicle. A number of 
standard engine tests are presently used which can be incorporated into 
this requirement.
    (c) When in the judgment of the Administrator a device cannot 
satisfactorily be evaluated using either dynamometer or track versions 
of the City Fuel Economy Test and the Highway Fuel Economy Test, the 
Administrator will select or design other procedures.