[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: 40CFR1048.240]

[Page 559-560]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1048_CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION 
ENGINES--Table of Contents
 
                  Subpart C_Certifying Engine Families
 
Sec. 1048.240  How do I demonstrate that my engine family complies with 
exhaust emission standards?

    (a) For certification, your engine family is considered in 
compliance with the numerical emission standards in Sec. 1048.101 (a) 
and (b), if all emission-data engines representing that family have test 
results showing emission levels at or below these standards.
    (b) Your engine family does not comply if any emission-data engine 
representing that family has test results showing emission levels above 
the standards from Sec. 1048.101 (a) and (b) for any pollutant.
    (c) To compare emission levels from the test engine with the 
emission standards, apply deterioration factors to the measured emission 
levels. The deterioration factor is a number that shows the relationship 
between exhaust emissions at the end of useful life and at the low-hour 
test point. Specify the deterioration factors based on emission 
measurements using four significant figures, consistent with good 
engineering judgment. For example, deterioration factors must be 
consistent with emission increases observed from in-use testing with 
similar engines (see subpart E of this part). Small-volume engine 
manufacturers may use assigned deterioration factors that we establish. 
Apply the deterioration factors as follows:
    (1) For engines that use aftertreatment technology, such as 
catalytic converters, the deterioration factor is the ratio of exhaust 
emissions at the end of useful life to exhaust

[[Page 560]]

emissions at the low-hour test point. Adjust the official emission 
results for each tested engine at the selected test point by multiplying 
the measured emissions by the deterioration factor. If the factor is 
less than one, use one.
    (2) For engines that do not use aftertreatment technology, the 
deterioration factor is the difference between exhaust emissions at the 
end of useful life and exhaust emissions at the low-hour test point. 
Adjust the official emission results for each tested engine at the 
selected test point by adding the factor to the measured emissions. If 
the factor is less than zero, use zero.
    (d) After adjusting the emission levels for deterioration, round 
them to the same number of decimal places as the emission standard. 
Compare the rounded emission levels to the emission standard for each 
test engine.