[Code of Federal Regulations]

[Title 40, Volume 31]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR1051.240]



[Page 635-636]

 

                   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 C_Certifying Engine Families

 

Sec.  1051.240  How do I demonstrate that my engine family complies with 

exhaust emission standards?



    (a) For purposes of certification, your engine family is considered 

in compliance with the applicable numerical exhaust emission standards 

in subpart B of this part if all emission-data vehicles representing 

that family have test results showing deteriorated emission levels at or 

below these standards. (Note: if you participate in the ABT program in 

subpart H of this part, your FELs are considered to be the applicable 

emission standards with which you must comply.)

    (b) Your engine family is deemed not to comply if any emission-data 

vehicle representing that family has test results showing a deteriorated 

emission level above an applicable FEL or emission standard from subpart 

B of this part for any pollutant.

    (c) To compare emission levels from the emission-data vehicle with 

the applicable emission standards, apply deterioration factors to the 

measured emission levels. Section 1051.243 specifies how to test your 

vehicle to develop deterioration factors that represent the 

deterioration expected in emissions over your vehicle's full useful 

life. Your deterioration factors must take into account any available 

data from in-use testing with similar engines. Small-volume 

manufacturers may use assigned deterioration factors that we establish. 

Apply deterioration factors as follows:



[[Page 636]]



    (1) For vehicles that use aftertreatment technology, such as 

catalytic converters, use a multiplicative deterioration factor for 

exhaust emissions. A multiplicative deterioration factor for a pollutant 

is the ratio of exhaust emissions at the end of the useful life and 

exhaust emissions at the low-hour test point. In these cases, adjust the 

official emission results for each tested vehicle or engine at the 

selected test point by multiplying the measured emissions by the 

deterioration factor. If the factor is less than one, use one. 

Multiplicative deterioration factors must be specified to three 

significant figures.

    (2) For vehicles that do not use aftertreatment technology, use an 

additive deterioration factor for exhaust emissions. An additive 

deterioration factor for a pollutant is the difference between exhaust 

emissions at the end of the useful life and exhaust emissions at the 

low-hour test point. In these cases, adjust the official emission 

results for each tested vehicle or engine at the selected test point by 

adding the factor to the measured emissions. If the factor is less than 

zero, use zero. Additive deterioration factors must be specified to one 

more decimal place than the applicable standard.

    (d) Collect emission data using measurements to one more decimal 

place than the applicable standard. Apply the deterioration factor to 

the official emission result, as described in paragraph (c) of this 

section, then round the adjusted figure to the same number of decimal 

places as the emission standard. Compare the rounded emission levels to 

the emission standard for each emission-data vehicle. In the case of 

HC+NOX standards, add the emission results and apply the 

deterioration factor to the sum of the pollutants before rounding. 

However, if your deterioration factors are based on emission 

measurements that do not cover the vehicle's full useful life, apply the 

deterioration factor to each pollutant and then add the results before 

rounding.



[70 FR 40496, July 13, 2005]