[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1051.520]

[Page 632]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1051_CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES
--Table of Contents
 
                        Subpart F_Test Procedures
 
Sec. 1051.520  How do I perform exhaust durability testing?

    This section applies for durability testing to determine 
deterioration factors for exhaust emissions. Small-volume manufacturers 
may omit durability testing if they use our assigned deterioration 
factors that we establish based on our projection of the likely 
deterioration in the performance of specific emission controls.
    (a) Calculate your deterioration factor by testing a vehicle or 
engine that is representative of your engine family at a low-hour test 
point and the end of its useful life. You may also test at intermediate 
points.
    (b) Operate the vehicle or engine over a representative duty cycle 
for a period at least as long as the useful life (in hours or 
kilometers). You may operate the vehicle or engine continuously.
    (c) You may perform critical emission-related maintenance during 
durability testing, consistent with Sec. 1051.125(a). You may not 
perform any other emission-related maintenance during durability 
testing.
    (d) Use a linear least-squares fit of your test data for each 
pollutant to calculate your deterioration factor.
    (e) You may ask us to allow you to use other testing methods to 
determine deterioration factors, consistent with good engineering 
judgment.