(Grams per mile)
|Engine type and pollutant||Prior to controld||1968-
|Interim Tier 2i
|HC (total)||11||g||2.2||3.4||3.4||1.5||1.5||0.41||0.41||0.41||0.41||0.41 (h)||h||h|
|NMOG||e||h||h||h||h||h||h||h||h||h||h||h||0.125 (0.156)||0.100 (0.125)|
|CO||80||g||23||39||39||15||15||7.0||3.4||3.4||3.4||3.4 (4.2)||3.4 (4.2)||3.4 (4.2)|
|Cold-temp. COc||e||h||h||h||h||h||h||h||h||h||h||10 (h)||10 (h)||10 (h)|
|NOx||4||h||h||h||3.0||3.1||2.0||2.0||1.0||1.0||1.0||0.4 (0.6)||0.4 (0.6)||0.14 (0.20)|
|Particulates||e||h||h||h||h||h||h||h||h||h||h||0.08 (0.10)||0.08 (0.08)||0.02 (0.02)|
|Formaldehyde||e||h||h||h||h||h||h||h||h||h||h||h||0.015 (0.018)||0.015 (0.018)|
|HC (total)||11||h||h||h||h||1.5||1.5||0.41||0.41||0.41||0.41||0.41 (h)||h||h|
|NMOG||e||h||h||h||h||h||h||h||h||h||h||h||h (0.156)||0.100 (0.125)|
|CO||80||h||h||h||h||15||15||7.0||3.4||3.4||3.4||3.4 (4.2)||h (4.2)||3.4 (4.2)|
|NOx||4||h||h||h||h||3.1||2.0||2.0||1.0||1.0||1.0||1.0 (1.25)||h (0.6)||0.14 (0.20)|
|Particulates||e||h||h||h||h||h||h||h||h||0.60||0.20||0.08 (0.10)||h (0.10)||0.02 (0.02)|
|Formaldehyde||e||h||h||h||h||h||h||h||h||h||h||h||h (0.018)||0.015 (0.018)|
|Useful life (intermediate)b,f||h||h||h||h||h||h||h||h||h||h||5 years/50,000 miles||5 years/50,000 miles||5 years/50,000 miles|
|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||5 years/50,000 miles||10 years/100,000 miles||10 years/100,000 miles||10 years/120,000 miles|
KEY: CO = carbon monoxide; HC = hydrocarbons; NMHC = non-methane hydrocarbons; NMOG = nonmethane organic gases; NOx = nitrogen oxides.
a The test procedure for measuring exhaust emissions has changed several times over the course of vehicle emissions regulations. 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 under the new Supplemental Federal Test Procedure will be phased-in beginning with model year 2000; these standards are not shown in this table.
b All emissions standards must be met for a useful life of 5 years/50,000 miles. Beginning with model year 1994, a second set of emissions standards must also be met for a full useful life of 10 years/100,000 miles; these standards are shown in parentheses. Tier 1 exhaust standards were phased-in during 1994-96 at a rate of 40%, 80%, and 100%, respectively.
c 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.
d The "Prior to control" column reports emissions estimates of a typical newly manufactured car in the years before exhaust emissions certification standards were implemented.
e No estimate available.
f Manufacturers can opt to certify vehicles for a full useful life of 15 years/150,000 miles and have either 1) intermediate useful life standards waived or 2) receive additional NOx credits.
g In 1968-69, exhaust emissions standards were issued in parts per million rather than grams per mile and are, therefore, incompatible with this table.
h No standard has been set.
i The term "tier" refers to a level of standards and is associated with 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 particulate matter; 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-weight corporate average NOx standard is met for the full useful life of the vehicle. 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 sales-weighted average for light-duty vehicles (LDVs) is 9.3 grams/mile. For LDVs, 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 LDVs 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.