[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: 40CFR1048.101]

[Page 546-548]
 
                   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 B_Emission Standards and Related Requirements
 
Sec. 1048.101  What exhaust emission standards must my engines meet?


    Apply the exhaust emission standards in this section by model year. 
You may choose to certify engines earlier than we require. The Tier 1 
standards apply only to steady-state testing, as described in paragraph 
(b) of this section. The Tier 2 standards apply to steady-state, 
transient, and field testing, as described in paragraphs (a), (b), and 
(c) of this section.
    (a) Standards for transient testing. Starting in the 2007 model 
year, Tier 2 exhaust emission standards apply for transient measurement 
of emissions with the duty-cycle test procedures in subpart F of this 
part:
    (1) The Tier 2 HC+NOX standard is 2.7 g/kW-hr and the 
Tier 2 CO standard is 4.4 g/kW-hr. For severe-duty engines, the Tier 2 
HC+NOX standard is 2.7 g/kW-hr and the Tier 2 CO standard is 
130.0 g/kW-hr. The standards in this paragraph (a) do not apply for 
transient testing of high-load engines.
    (2) You may optionally certify your engines according to the 
following formula instead of the standards in paragraph (a)(1) of this 
section: (HC+NOX) x CO \0.784\ <= 8.57. The HC+NOX 
and CO emission levels you select to satisfy this formula, rounded to 
the nearest 0.1 g/kW-hr, become the emission standards that apply for 
those engines. You may not select an HC+NOX emission standard 
higher than 2.7 g/kW-hr or a CO emission standard higher than 20.6 g/kW-
hr. The following table illustrates a range of possible values under 
this paragraph (a)(2):

   Table 1 of Sec. 1048.101--Examples of Possible Tier 2 Duty-cycle
                           Emission Standards
------------------------------------------------------------------------
                                                              CO  (g/kW-
                     HC+NOX  (g/kW-hr)                           hr)
------------------------------------------------------------------------
2.7........................................................          4.4
2.2........................................................          5.6
1.7........................................................          7.9
1.3........................................................         11.1
1.0........................................................         15.5
0.8........................................................         20.6
------------------------------------------------------------------------

    (b) Standards for steady-state testing. Except as we allow in 
paragraph (d) of this section, the following exhaust emission standards 
apply for steady-state measurement of emissions with the duty-cycle test 
procedures in subpart F of this part:
    (1) The following table shows the Tier 1 exhaust emission standards 
that apply to engines from 2004 through 2006 model years:

                         Table 2 of Sec. 1048.101--Tier 1 Emission Standards (g/kW-hr)
----------------------------------------------------------------------------------------------------------------
                                                                  General emission         Alternate emission
                                                                      standards           standards for severe-
                           Testing                           --------------------------       duty  engines
                                                                                       -------------------------
                                                                 HC+NOX         CO         HC+NOX         CO
----------------------------------------------------------------------------------------------------------------
Certification and production-line testing...................          4.0         50.0          4.0        130.0
In-use testing..............................................          5.4         50.0          5.4        130.0
----------------------------------------------------------------------------------------------------------------

    (2) Starting in the 2007 model year, engines must meet the Tier 2 
exhaust emission standards in paragraph (a) of this section for both 
steady-state and transient testing. See paragraph (d) of this section 
for alternate standards that apply for certain engines.
    (c) Standards for field testing. Starting in 2007, the following 
Tier 2 exhaust emission standards apply for emission measurements with 
the field-testing procedures in subpart F of this part:
    (1) The HC+NOX standard is 3.8 g/kW-hr and the CO 
standard is 6.5 g/kW-hr. For severe-duty engines, the HC+NOX

[[Page 547]]

standard is 3.8 g/kW-hr and the CO standard is 200.0 g/kW-hr. For 
natural gas-fueled engines, you are not required to measure nonmethane 
hydrocarbon emissions or total hydrocarbon emissions for testing to show 
that the engine meets the emission standards of this paragraph (c); that 
is, you may assume HC emissions are equal to zero.
    (2) You may apply the following formula to determine alternate 
emission standards that apply to your engines instead of the standards 
in paragraph (c)(1) of this section: (HC+NOX) x CO\0.791\ <= 
16.78. HC+NOX emission levels may not exceed 3.8 g/kW-hr and 
CO emission levels may not exceed 31.0 g/kW-hr. The following table 
illustrates a range of possible values under this paragraph (c)(2):

  Table 3 of Sec. 1048.101--Examples of Possible Tier 2 Field-testing
                           Emission Standards
------------------------------------------------------------------------
                                                              CO  (g/kW-
                     HC+NOX  (g/kW-hr)                           hr)
------------------------------------------------------------------------
3.8........................................................          6.5
3.1........................................................          8.5
2.4........................................................         11.7
1.8........................................................         16.8
1.4........................................................         23.1
1.1........................................................         31.0
------------------------------------------------------------------------

    (d) Engine protection. For engines that require enrichment at high 
loads to protect the engine, you may ask to meet alternate Tier 2 
standards of 2.7 g/kW-hr for HC+NOX and 31.0 g/kW-hr for CO 
instead of the emission standards described in paragraph (b)(2) of this 
section for steady-state testing. If we approve your request, you must 
still meet the transient testing standards in paragraph (a) of this 
section and the field-testing standards in paragraph (c) of this 
section. To qualify for this allowance, you must do all the following 
things:
    (1) Show that enrichment is necessary to protect the engine from 
damage.
    (2) Show that you limit enrichment to operating modes that require 
additional cooling to protect the engine from damage.
    (3) Show in your application for certification that enrichment will 
rarely occur in use in the equipment in which your engines are 
installed. For example, an engine that is expected to operate 5 percent 
of the time in use with enrichment would clearly not qualify.
    (4) Include in your installation instructions any steps necessary 
for someone installing your engines to prevent enrichment during normal 
operation (see Sec. 1048.130).
    (e) Fuel types. Apply the exhaust emission standards in this section 
for engines using each type of fuel specified in 40 CFR part 1065, 
subpart C, for which they are designed to operate. You must meet the 
numerical emission standards for hydrocarbons in this section based on 
the following types of hydrocarbon emissions for engines powered by the 
following fuels:
    (1) Gasoline- and LPG-fueled engines: THC emissions.
    (2) Natural gas-fueled engines: NMHC emissions.
    (3) Alcohol-fueled engines: THCE emissions.
    (f) Small engines. Certain engines with total displacement at or 
below 1000 cc may comply with the requirements of 40 CFR part 90 instead 
of complying with the requirements of this part, as described in Sec. 
1048.615.
    (g) Useful life. Your engines must meet the exhaust emission 
standards in paragraphs (a) through (c) of this section over their full 
useful life (Sec. 1048.240 describes how to use deterioration factors 
to show this). The minimum useful life is 5,000 hours of operation or 
seven years, whichever comes first.
    (1) Specify a longer useful life in hours for an engine family under 
either of two conditions:
    (i) If you design, advertise, or market your engine to operate 
longer than the minimum useful life (your recommended hours until 
rebuild may indicate a longer design life).
    (ii) If your basic mechanical warranty is longer than the minimum 
useful life.
    (2) You may request a shorter useful life for an engine family if 
you have documentation from in-use engines showing that these engines 
will rarely operate longer than the alternate useful life. The useful 
life value may not be shorter than any of the following:
    (i) 1,000 hours of operation.
    (ii) Your recommended overhaul interval.

[[Page 548]]

    (iii) Your mechanical warranty for the engine.
    (h) Applicability for testing. The standards in this subpart apply 
to all testing, including production-line and in-use testing, as 
described in subparts D and E of this part.