[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: 40CFR1048.230]

[Page 558]
 
                   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. 1048.230  How do I select engine families?

    (a) Divide your product line into families of engines that you 
expect to have similar emission characteristics. Your engine family is 
limited to a single model year.
    (b) Group engines in the same engine family if they are the same in 
all of the following aspects:
    (1) The combustion cycle.
    (2) The cooling system (water-cooled vs. air-cooled).
    (3) Configuration of the fuel system (for example, fuel injection 
vs. carburetion).
    (4) Method of air aspiration.
    (5) The number, location, volume, and composition of catalytic 
converters.
    (6) The number, arrangement, and approximate bore diameter of 
cylinders.
    (7) Evaporative emission controls.
    (c) In some cases you may subdivide a group of engines that is 
identical under paragraph (b) of this section into different engine 
families. To do so, you must show you expect emission characteristics to 
be different during the useful life or that any of the following engine 
characteristics are different:
    (1) Method of actuating intake and exhaust timing (poppet valve, 
reed valve, rotary valve, etc.).
    (2) Location or size of intake and exhaust valves or ports.
    (3) Configuration of the combustion chamber.
    (4) Cylinder stroke.
    (5) Exhaust system.
    (6) Type of fuel.
    (d) If your engines are not identical with respect to the things 
listed in paragraph (b) of this section, but you show that their 
emission characteristics during the useful life will be similar, we may 
approve grouping them in the same engine family.
    (e) If you cannot appropriately define engine families by the method 
in this section, we will define them based on features related to 
emission characteristics.
    (f) You may ask us to create separate families for exhaust emissions 
and evaporative emissions. If we do this, list both families on the 
emission control information label.
    (g) Where necessary, you may divide an engine family into sub-
families to meet different emission standards, as specified in Sec. 
1048.101(a)(2). For issues related to compliance and prohibited actions, 
we will generally apply decisions to the whole engine family. For engine 
labels and other administrative provisions, we may approve your request 
for separate treatment of sub-families.