|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||1988-1989||1990||1991-1995||Tier 1k 1996-2007||Interim Tier 2k 2008||Tier 2k 2009+|
|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||0.80||0.80||j (0.8)||j||j|
|NMOG||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j||0.160 (0.230)||0.125 (0.156)|
|CO||80||i||23||39||39||20||20||18||18||10||10||10||10||10||10||5 (7.3)||4.4 (6.4)||3.4 (4.2)|
|Cold-temp. COd||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j||12.5 (j)||12.5 (j)||12.5 (j)|
|NOx||4||j||j||j||3.0||3.1||3.1||2.3||2.3||2.3||2.3||2.3||2.3||1.7||1.7||1.1 (1.53)||0.4 (0.6)||0.14 (0.20)|
|Particulates||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j (0.12)||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||0.018 (0.027)||0.015 (0.018)|
|HC (total)||11||j||j||j||j||j||2.0||1.7||1.7||0.80||0.80||0.80||0.80||0.80||0.80||j (0.8)||j||j|
|NMOG||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j (0.230)||0.125 (0.156)|
|CO||80||j||j||j||j||j||20||18||18||10||10||10||10||10||10||5 (7.3)||j (6.4)||3.4 (4.2)|
|NOx||4||j||j||j||j||j||3.1||2.3||2.3||2.3||2.3||2.3||2.3||1.7||1.7||j (1.53)||j (0.6)||0.14 (0.20)|
|Particulates||h||j||j||j||j||j||j||j||0.60||0.60||0.60||0.50||0.45||0.45||0.13||j (0.12)||j (0.08)||0.02 (0.02)|
|Formaldehyde||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j||j (0.027)||0.015 (0.018)|
|LDT4 weight criteriae||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||Any ALVW||Any ALVW||Any ALVW||ALVW over 5,750 pounds||ALVW over 5,750 pounds||ALVW over 5,750 pounds|
|LDT4 weight criteriae||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 6,001-8,500 pounds||GVWR 6,001-8,500 pounds||GVWR 6,001-8,500 pounds||GVWR 6,001-8,500 pounds||GVWR 6,001-8,500 pounds||GVWR 6,001-8,500 pounds|
|Useful life, intermediatec,f||j||j||j||j||j||j||j||j||j||j||j||j||j||j||5 years/50,000 miles||6 years/50,000 miles||7 years/50,000 miles|
|Useful life, full||5 years/50,000 miles||6 years/50,000 miles||7 years/50,000 miles||8 years/50,000 miles||9 years/50,000 miles||10 years/50,000 miles||11 years/50,000 miles||12 years/50,000 miles||13 years/50,000 miles||11 years/120,000 miles||12 years/120,000 miles||13 years/120,000 miles||14 years/120,000 miles||15 years/120,000 miles||16 years/120,000 miles||17 years/120,000 miles||18 years/120,000 miles|
KEY: ALVW=adjusted loaded vehicle weight; CO = carbon monoxide; GVWR=gross vehicle weight rating; HC = hydrocarbons; NMHC=nonmethane hydrocarbon; 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 LDT1, LDT2, and LDT3 are given in tables 4-30a, 4-40b, and 4-30c.
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 the 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 2002. These standards are not shown in this table.
c Emissions standards had to be met for a full 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 1996, emissions standards were established for an intermediate useful life of 5 years/50,000 miles as well as a full useful life of 11 years/120,000 miles (intermediate and full useful life standards are shown in parentheses). This applied to all pollutants except HC and particulates for all LDT4 vehicles and NOx for diesel-powered LDT4 vehicles, which were only required to meet full useful life standards. Tier 1 exhaust standards were phased-in during 1996-97 at a rate of 50% and 100%, respectively.
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. ALVW is the numerical average of the GVWR and the curb weight.
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 waived or (2) receive additional NOx credits.
g The "Prior to control" column reports emissions estimates of a typical newly manufactured car in the years before exhaust emissions certification standards 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 2 refers to an intermediate level of standards that moves 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 particulate matter (HC and non-methane HC 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 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 LDT4 vehicles is 0.6 grams/mile. Tier 2 standards will be phased in during 2008 and 2009. In 2008, 50% of LDT4 vehicles must meet Tier 2 standards; the others must meet Interim Tier 2 standards. Beginning in 2009, all LDT4 vehicles must meet Tier 2 standards.
40 CFR 86, Subpart A (July 1, 2000).
Federal Register, Vol. 65, No. 28, pp. 6851-6858.