[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: 40CFR1051.230]



[Page 633-634]

 

                   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.  1051.230  How do I select engine families?



    (a) Divide your product line into families of vehicles that are 

expected to have similar emission characteristics throughout the useful 

life. Except as specified in paragraph (f) of this section, you must 

have separate engine families for meeting exhaust and evaporative 

emissions. Your engine family is limited to a single model year.

    (b) For exhaust emissions, group vehicles in the same engine family 

if they are the same in all the following aspects:

    (1) The combustion cycle.

    (2) The cooling system (liquid-cooled vs. air-cooled).

    (3) Configuration of the fuel system (for example, port fuel 

injection vs. carburetion).

    (4) Method of air aspiration.

    (5) The number, location, volume, and composition of catalytic 

converters.

    (6) Type of fuel.

    (7) The number, arrangement, and approximate bore diameter of 

cylinders.

    (8) Numerical level of the emission standards that apply to the 

vehicle.

    (c) For evaporative emissions, group vehicles in the same engine 

family if fuel tanks are similar and fuel lines are similar considering 

all the following aspects:

    (1) Type of material (including additives such as pigments, 

plasticizers, and UV inhibitors).

    (2) Emission-control strategy.



[[Page 634]]



    (3) Production methods. This does not apply to differences in 

production methods that would not affect emission characteristics.

    (d) You may subdivide a group of vehicles that is identical under 

paragraph (b) or (c) of this section into different engine families if 

you show the expected emission characteristics are different during the 

useful life.

    (e) You may group vehicles that are not identical with respect to 

the things listed in paragraph (b) or (c) of this section in the same 

engine family, as follows:

    (1) You may group such vehicles in the same engine family if you 

show that their emission characteristics during the useful life will be 

similar.

    (2) If you are a small-volume manufacturer, you may group engines 

from any vehicles subject to the same emission standards into a single 

engine family. This does not change any of the requirements of this part 

for showing that an engine family meets emission standards.

    (f) You may divide your product line into engine families based on a 

combined consideration of exhaust and evaporative emission-control 

systems, consistent with the requirements of this section. This would 

allow you to use a single engine-family designation for each engine 

family instead of having separate engine-family designations for exhaust 

and evaporative emission-control systems for each model.

    (g) Select test engines from the engine family as described in 40 

CFR 1065.401. Select test components related to evaporative emission-

control systems that are most likely to exceed the applicable emission 

standards. For example, select a fuel tank with the smallest average 

wall thickness (or barrier thickness, as appropriate) of those tanks you 

include in the same family.



[70 FR 40495, July 13, 2005]