(Grams per mile)
|Engine type and pollutant||Prior to controlg||1968-
|Interim Tier 2k
|HC (total)||11||e||2.2||3.4||3.4||2.0||2.0||1.7||1.7||0.80||0.80||0.80||0.80||0.80||j (0.80)||j (0.80)||j||j|
|NMHC||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j (0.40)||j (0.40)||j||j|
|NMOG||h||j||j||j||j||j||j||j||j||j||j||j||j||j||j (5.5)||j||0.125||0.100 (0.125)|
|CO||80||I||23||39||39||20||20||18||18||10||10||10||10||10||4.4 (5.5)||4.4 (5.5)||3.4||3.4|
|Cold-temp. COd||h||j||j||j||j||j||j||j||j||j||j||j||j||j||12.5 (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||1.7||1.7||0.7 (0.97)||0.7 (0.97)||0.4||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||0.02 (0.02)|
|HC (total)||11||j||j||j||j||j||2.0||1.7||1.7||0.80||0.80||0.80||0.80||0.80||j (0.80)||j (0.80)||j||j|
|NMHC||h||j||j||j||j||j||j||j||j||j||j||j||j||j||0.3 (0.40)||0.3 (0.40)||j||j|
|CO||80||j||j||j||j||j||20||18||18||10||10||10||10||10||4.4 (5.5)||4.4 (5.5)||j||3.4 (4.2)|
|NOx||4||j||j||j||j||j||3.1||2.3||2.3||2.3||2.3||2.3||1.7||1.7||j (0.97)||j (0.97)||j||0.14 (0.20)|
|Particulates||h||j||j||j||j||j||j||j||0.60||0.60||0.60||0.50||0.45||0.13||0.13||0.08 (0.10)||j||0.02 (0.02)|
|LDT2 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 up through 6,000 pounds; LVW over 3,750 pounds||GVWR up through 6,000 pounds; LVW over 3,750 pounds||GVWR up through 6,000 pounds; LVW over 3,750 pounds||GVWR up through 6,000 pounds; LVW over 3,750 pounds||GVWR up through 6,000 pounds; LVW over 3,750 pounds||GVWR up through 6,000 pounds; LVW over 3,750 pounds|
|Useful life (intermediate)c, f||j||j||j||j||j||j||j||j||j||j||j||j||j||5 years/50,000 miles||5 years/50,000 miles||5 years/50,000miles||5 years/50,000miles|
|Useful life (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||11 years/120,000 miles||10 years/100,000 miles||10 years/100,000 miles||10 years/100,000 miles||10 years/120,000 miles|
KEY: CO=carbon monoxide; GVWR=gross vehicle weight rating; HC=hydrocarbons; LVW=loaded vehicle weight; NMHC=non-methane hydrocarbons; 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 LDT1, LDT3, and LDT4 are shown in tables 4-30a, 4-40c, and 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 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 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. Particulates 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 degrees F (rather than 75 degrees F) 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 waived or (2) receive additional NOx credits.
g The "Prior to controls" reports emissions estimates of a typical newly manufactured car in the years before exhaust emissions certification standards were implemented.
h No estimate available.
iIn 1968-69, exhaust emissions standards were issued in parts per million rather than grams per mile and are, therefore, incompatible with this table.
jNo 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 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 LDT2 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 LDT2 vehicles not meeting the Tier 2 standards must meet Interim Tier 2 standards.
40 CFR 86, Subpart A (July 1, 2000) Federal Register, Vol. 65, No. 28, pp. 6851-6858.