# Table 4-31: Federal Exhaust Emission Certification Standards for Newly Manufactured Gasoline- and Diesel-Powered Light-Duty Trucks (Category LDT1)

(Grams per mile)

Engine type and pollutant Prior to controlg 1968-1969 1970-1971 1972 1973-1974 1975 1976-1978 1979-1981 1982-1983 1984 1985-1986 1987 1988-1993 Tier 1k 1994 1995-2003 Interim Tier 2k 2004-2006 Tier 2k 2007+
Gasoline
HC (total) 11 i 2.2 3.4 3.4 2.0 2.0 1.7 1.7 0.80 0.80 0.80 0.80 j R(0.80) j R(0.80) j j j j
NMHC h j j j j j j j j j j j j 0.25 (0.31) 0.25 (0.31) j j j j
NMOG h j j j j j j j j j j j j j j j j 0.125 (0.156) 0.100 (0.125)
CO 80 i 23 39 39 20 20 18 18 10 10 10 10 3.4 (4.2) 3.4 (4.2) 3.4 (4.2) 3.4 (4.2)
Cold-temp. COd e j j j j j j j j j j j j 10 j 10 j 10 j 10 j
NOx 4 j j j 3.0 3.1 3.1 2.3 2.3 2.3 2.3 2.3 1.2 0.4 (0.6) 0.4 (0.6) 0.4 (0.6) 0.14 (0.20)
Particulates h j j j j j j j j j j j j j j 0.08 (0.10) 0.08 (0.08) 0.02 (0.02)
Formaldehyde h j j j j j j j j j j j j j j j j 0.015 (0.018) 0.015 (0.018)
Diesel
HC (total) 11 j j j j j 2.0 1.7 1.7 0.80 0.80 0.80 0.80 j (0.80) j (0.80) j j j j
NMHC h j j j j j j j j j j j j 0.25 (0.31) 0.25 (0.31) j j j j
NMOG h j j j j j j j j j j j j j j j j j (0.156) 0.100 (0.125)
CO 80 j j j j j 20 18 18 10 10 10 10 3.4 (4.2) 3.4 (4.2) j (4.2) 3.4 (4.2)
NOx 4 j j j j j 3.1 2.3 2.3 2.3 2.3 2.3 1.2 1.0 (1.25) 1.0 (1.25) j (0.6) 0.14 (0.20)
Particulates h j j j j j j j 0.60 0.60 0.60 0.26 0.26 0.26 0.26 0.08 (0.10) j (0.10) 0.02 (0.02)
Formaldehyde h j j j j j j j j j j j j j j j j j (0.018) 0.015 (0.018)
LDT1 weight criterae   GVWR up through 6,000 pounds GVWR up through 6,000 pounds GVWR up through 6,000 pounds GVWR up through 6,000 pounds GVWR up through 6,000 pounds GVWR up through 6,000 pounds GVWR up through 8,500 pounds GVWR up through 8,500 pounds GVWR up through 8,500 pounds GVWR up through 8,500 pounds GVWR up through 8,500 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds GVWR up through 6,000 lbs; LVW up through 3,750 pounds
Test procedure b   7-mode   CVS-72 CVS-72 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75 CVS-75
Useful life, (intermediate) c,f
(full)
j j j j j j j j j j j j 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000miles 5 years/50,000miles 5 years/50,000miles 5 years/50,000miles
Useful life, (intermediate) c,f
(full)
5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 5 years/50,000 miles 11 years/120,000 miles 11 years/120,000 miles 11 years/120,000 miles 10 years/100,000 miles 10 years/100,000 miles 10 years/100,000 miles 10 years/100,000 miles 10 years/100,000 miles 10 years/100,000 miles 10 years/ 20,000 miles 10 years/ 20,000 miles

KEY: CO=carbon monoxide; CVS = constant volume sampler; GVWR=gross
vehicle weight rating; HC=hydrocarbons; LVW=loaded vehicle weight; NMHC=nonmethane
hydrocarbons; NMOG= nonmethane organic gases; NOx=nitrogen oxides.

a Light-duty truck categories LDT1-LDT4 were not created until 1994.
From 1968 to 1978, all trucks with a GVWR up to 6,000 pounds were classified
as light-duty trucks and were required to meet the same standards. As of 1979,
the maximum weight was raised to 8,500 pounds GVWR. During 1988-93, light duty
trucks were divided into two subcategories that coincide with the current LDT1-LDT4
categories. The standards for LDT2, LDT3, and LDT4 are shown in tables 4-30b
through 4-30d.

b The test procedure for measuring exhaust emissions has changed
several times over the course of vehicle emissions regulation. The 7-mode procedure
was used through model year 1971 and was replaced by the CVS-72 procedure beginning
in model year 1972. The CVS-75 procedure became the test procedure as of model
year 1975. While it may appear that total HC and CO standards were relaxed in
1972-74, these standards were actually more stringent due to the more stringent
nature of the CVS-72 test procedure. Additional standards for CO and composite
standards for NMHC and NOx tested over the new Supplemental Federal Test Procedure
will be phased-in beginning with model year 2000. These standards are not shown
in this table.

c Emissions standards had to be met for a useful life of 5 years/50,000
miles through model year 1983, and a full useful life of 11 years/120,000 miles
was defined for 1985-93 (several useful life options were available for 1984).
Beginning in model year 1994, emissions standards were established for an intermediate
useful life of 5 years/50,000 miles as well as a full useful life (full useful
life standards are shown in parentheses). HC standards, however, were established
only for full useful life. Tier 1 exhaust standards, except particulates standards,
were phased in during 1994-96 at a rate of 40%, 80%, and 100%, respectively.
Particulate matter standards were phased-in at a rate of 40%, 80%, and 100%
during 1995-97.

d The cold CO emissions standard is measured at 20 0F
(rather than 75 0F) and is applicable for a 5-year/50,000-mile useful
life.

e GVWR is the maximum design loaded weight. LVW is the curb weight
(nominal vehicle weight) plus 300 pounds.

f Manufacturers can opt to certify vehicles for a full useful life
of 15 years/150,000 miles and either have (1) intermediate useful life standards

g The "Prior to controls" column reports emissions estimates
of a typical newly manufactured car in the years before exhaust emissions certification
standard were implemented.

h No estimate available.

I In 1968-69, exhaust emissions standards were issued in parts per
million rather than grams per mile and are, therefore, incompatible with this
table.

j No standard has been set.

k The term "tier" refers to a level of standards for specific
years. Interim Tier 2 refers to an intermediate level of standards that move
manufacturers toward compliance with Tier 2 standards. Interim Tier 2 and Tier
2 standards are established as "bins." Each bin is a set of standards
for NOx, CO, NMOG, formaldehyde, and particulates (HC and NMHC standards are
dropped for Tier 2 and Interim Tier 2). Manufacturers may certify any given
vehicle family to any of the bins available for that vehicle class as long as
the resulting sales-weighted corporate average NOx standard is met for the full
useful life. The Tier 2 corporate average NOx standard is 0.07 grams/mile. Interim
corporate-based average NOx standards are based on vehicle type. The interim
corporate sales-weighted average for LDT1 vehicles is 0.3 grams/mile. Tier 2
standards will be phased in at a rate of 25% in 2004, 50% in 2005, 75% in 2006,
and 100% in 2007. During this period, all LDT1 vehicles not meeting the Tier
2 standards must meet Interim Tier 2 standards.

SOURCES

40 CFR 86, Subpart A (July 1, 2000).

Federal Register, Vol. 65, No. 28, pp. 6851-6858.

Updated: Sunday, May 21, 2017