Table 4-32a. Federal Exhaust Emissions Certification Standards for Newly Manufactured Gasoline- and Diesel-Powered Light Heavy-Duty Trucks (Grams per brake horsepower-hour)

Table 4-32a. Federal Exhaust Emissions Certification Standards for Newly Manufactured Gasoline- and Diesel-Powered Light Heavy-Duty Trucks (Grams per brake horsepower-hour)

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Engine type and pollutant 1970-73 1974-78 1979-83 1984 1985-86 1987 1988-89 1990 1991-93 1994-97 1998-2003 2004+
Gasoline                       
HC + NOx e 16 10 10 e e e e e e e e
HC f e 1.5 1.5 1.9 1.1 1.1 1.1 1.1 1.1 1.1 1.1
NOx 10.6 10.6 10.6 6.0 5.0 5.0 4.0 4.0
CO f 40 25 25 37.1 14.4 14.4 14.4 14.4 14.4 14.4 14.4
Diesel                       
HC + NOx e 16 10 e e e e e e e e e
HC f e 1.5 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3
NOx e e e 10.7 10.7 10.7 10.7 6.0 5.0 5.0 4.0 4.0
Nonmethane HC + NOx e e e e e e e e e e e 2.4g
CO f 40 25 15.5 15.5 15.5 15.5 15.5 15.5 15.5 15.5 15.5
Particulates e e e e e e 0.60 0.60 0.25 0.10 0.10 0.10
Smoke opacity (acceleration/lugging/peak) a 40/20/e 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 20/15/50
Weight criteria for light heavy-duty trucks bGVWR over 6,000 lbs GVWR over 6,000 lbs GVWR over 8,500 lbs GVWR over 8,500 lbs GVWR over 8,500 lbs GVWR 8,501 through 14,000 GVWR 8,501 through 14,000 GVWR 8,501 through 14,000 GVWR 8,501 through 14,000 GVWR 8,501 through 14,000 GVWR 8,501 through 14,000 GVWR 8,501 through 14,000
Test procedure (gasoline)c9-mode steady-state 9-mode steady-state 9-mode steady-state 9-mode steady-state MVMA transient MVMA transient MVMA transient MVMA transient MVMA transient MVMA transient MVMA transient MVMA transient
(diesel) c13-mode steady-state 13-mode steady-state 13-mode steady-state EPA transient EPA transient EPA transient EPA transient EPA transient EPA transient EPA transient EPA transient EPA transient
Useful life (gasoline) d5 years/
50,000 miles
5 years/
50,000 miles
5 years/
50,000 miles
5 years/
50,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles
8 years/
110,000 miles

a Smoke opacity is expressed in percentage for acceleration, lugging, and peak modes (acceleration/lugging/peak). Lugging is when a vehicle is carrying a load.
b Gross vehicle weight rating (GVWR) is the maximum design loaded weight.
c Several testing procedures have been used during the course of exhaust emissions control. A steady-state 9-mode test procedure (13-mode for diesel) was used for 1970-83 standards. For 1984, either the steady-state tests or the U.S. Environmental Protection Agency (EPA) transient test procedure could be used. For diesels, the EPA transient test was required from 1985 to the present. For gasoline-powered vehicles, either the EPA or the Motor Vehicle Manufacturers Association (MVMA) transient test procedure could be used during 1985-86, and the MVMA procedure was required thereafter.
d Emissions standards apply to the useful life of the vehicle. Useful life was 5 years/50,000 miles through 1983, and 8 years/110,000 miles for model year 1985 and after. 1984 was a transitional year in which vehicles could meet the older standard (and test procedure) or the newer one. Useful life requirement for gasoline-powered trucks meeting NOx standards for 1998 and after is 10 years/110,000 miles. The useful life requirements for heavy-duty diesel truck standards are more complex and vary by vehicle weight, pollutant, test procedure, and year. Consult the U.S. Code of Federal Regulations for further information.
e No standard set.
f Although emissions standards for HC and CO were in effect for these years, they were not measured in grams per brake horsepower-hour and are, therefore, incompatible with this table.
g Vehicles can meet a composite nonmethane HC and NOx standard of 2.5, given they meet a nonmethane HC standard of no more than 0.5.

KEY: CO = carbon monoxide; HC = hydrocarbon; NOX = nitrogen oxides.

SOURCES: 40 CFR 86, Subpart A (July 1, 1998); U.S. Environmental Protection Agency, Office of Air and Radiation, personnal communication, April 1999.

NOTE: Tables 4-31a and 4-31b are identical for diesel.