v>EPA
United States
Environmental Protection
Agency
Office of Transportation and Air Quality
EPA-420-B-16-018
March 2016
Heavy-Duty Highway Compression-Ignition Engines and Urban Buses: Exhaust Emission Standards
Federal b
Year
1974-78
1979-84
1985-87
1988-89
1990
1991-93
1994-97
1998-2003
2004-2006 h
2007+ h' k' '• m' n
HC
(g/bhp-hr)
-
1.5
1.3
1.3d
1.3d
1.3
1.3
1.3
-
-
NMHC
(g/bhp-hr)
-
-
-
-
-
-
-
-
-
0.14°
NMHC +
NOx g/bhp-hr)
16
10
-
-
-
-
-
-
2. 4 (or 2. 5 with
a limit of 0.5 on
NMHC) ° [ABT '•']
2. 4 (or 2. 5 with
a limit of 0.5 on
NMHC) [ABT]
NOx
(g/bhp-hr)
-
-
10.7
10.7
6.0
5.0 [ABT]
5.0 [ABT]
4.0 [ABT]
-
0.2°
PM
(g/bhp-hr)
-
-
-
0.6
0.6
0.25 [ABT]
0.10e
0.1 [ABT]
0.07f, 0.05 a
0.1 [ABT]
0.059
0.1
0.059
0.01
CO
(gbhp-hr)
40
25
15.5
15.5
15.5
15.5
15.5
15.5
15.5
15.5
Idle CO
(percent
exhaust
gas flow)
-
-
-
0.5°
0.5°
0.5°
0.5°
0.5°
0.5
0.5
Smoke a
(Percentage)
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
20/15/50
Useful Life
(hours/years/miles)
-
-
LHDDE:-/8/ 110,000
MHDDE:-/ 8/185,000
HHDDE:-/8/290,000
1990-97 and 1998+ for
HC, CO, and PM:
LHDDE:-/8/ 110,000
MHDDE: -/8/ 185,000
HHDDE:-/8/290,000
1994+ urban buses for
PM only:
-/ 10/290,000
1998+ for NOx:
LHDDE:-/ 10/110,000
MHDDE:-/ 10/185,000
HHDDE:-/ 10/290,000
For all pollutants: p
LHDDE:-/ 10/110,000
MHDDE:-/ 10/185,000
HHDDE: 22,000 / 10 /
435,000
Warranty
Period
(years/miles)
-
-
-
5/100,000"
LHDDE:
5/50,000
All other HDDE:
5/100,000"
Notes:
The test procedures are the EPA Transient Test Procedure and the EPA Smoke Test
Procedure.
a Percentages apply to smoke opacity at acceleration/lug/peak modes.
b Standards for 1990 apply only to diesel-fueled heavy-duty engines (HDE). Stan-
dards for 1991+ apply to both diesel- and methanol-fueled HDEs. Standards that
apply to urban buses specifically are footnoted.
c This standard applies to the following fueled engines for the following model years:
methanol -1990+, natural gas and liquefied petroleum gas (LPG) -1994+.
d For petroleum-fueled engines, the standard is for hydrocarbons (HC). For metha-
nol-fueled engines, the standard is for total hydrocarbon equivalent (THCE).
e Certification standard for urban buses for 1993.
f Certification standard for urban buses from 1994-95.
g Certification standard for urban buses from 1996 and later. The in-use standard is
0.07.
h Load Response Test certification data submittal requirements take effect for heavy-
duty diesel engines beginning in model year 2004. The following requirements take
effect with the 2007 model year: steady-state test requirement and Not-to-Exceed
(NTE) test procedures for testing of in-use engines. On-board diagnostic require-
ments applicable to heavy-duty diesel vehicles and engines up to 14,000 pounds
gross vehicle weight rating (GVWR) phase in from the 2005 through 2007 model
years.
Continued
-------
i The modified averaging, banking, and trading program for 1998 and later model
year engines applies only to diesel cycle engines. Credits generated under the
modified program may be used only in 2004 and later model years.
j For heavy-duty diesel engines, there are three options to the measurement pro-
cedures currently in place for alternative fueled engines: (1) use a THC measure-
ment in place of an non-methane hydrocarbon (NMHC) measurement; (2) use a
measurement procedure specified by the manufacturer with prior approval of the
Administrator; or (3) subtract two percent from the measured THC value to obtain
an NMHC value. The methodology must be specified at time of certification and
will remain the same for the engine family throughout the engines' useful life. For
natural gas vehicles, EPA allows the option of measuring NMHC through direct
quantification of individual species by gas chromatography.
k Starting in 2006, refiners must begin producing highway diesel fuel that meets a
maximum sulfur standard of 15 parts per million (ppm).
I Subject to a Supplemental Emission Test (1.0 x Federal Test Procedure [FTP]
standard (or Family Emission Limit [FEL]) for nitrogen oxides [NOx], NMHC, and
particulate matter [PM]) and a NTE test (1.5 x FTP standard [or FEL] for NOx,
NMHC, and PM).
m EPA adopted the lab-testing and field-testing specifications in 40 CFR Part 1065 for
heavy-duty highway engines, including both diesel and Otto-cycle engines. These
procedures replace those previously published in 40 Code of Federal Regulations
(CFR) Part 86, Subpart N. Any new testing for 2010 and later model years must be
done using the 40 CFR Part 1065 procedures.
n Two-phase in-use NTE testing program for heavy-duty diesel vehicles. The pro-
gram begins with the 2007 model year for gaseous pollutants and 2008 for PM. The
requirements apply to diesel engines certified for use in heavy-duty vehicles (in-
cluding buses) with GVWRs greater than 8,500 pounds. However, the requirements
do not apply to any heavy-duty diesel vehicle that was certified using a chassis
dynamometer, including medium-duty passenger vehicles with GVWRs of between
8,500 and 10,000 pounds.
o NOx and NMHC standards will be phased in together between 2007 and 2010. The
phase-in will be on a percent-of-sales basis: 50 percent from 2007 to 2009 and 100
percent in 2010.
p Note that for an individual engine, if the useful life hours interval is reached before
the engine reaches 10 years or 100,000 miles, the useful life shall become 10
years or 100,000 miles, whichever occurs first, as required under Clean Air Act sec-
tion 202(d).
q Years or miles, whichever comes first but never less than the basic mechanical
warranty for the engine family.
Code of Federal Regulations (CFR) citations:
40 CFR 86.099-11 Emission standards for 1999 and later model year diesel heavy-
duty engines and vehicles.
40 CFR 86.004-11 Emission standards for 2004 and later model year diesel heavy-
duty engines and vehicles.
40 CFR 86.007-11 Emission standards and supplemental requirements for 2007
and later model year diesel heavy-duty engines and vehicles.
------- |