Vehicle Emission Standards

All new vehicles for sale in the United States are certified to meet emission standards. Vehicle emissions standards limit the amounts of criteria pollutants emitted from a vehicle’s tailpipe and leaks in its fuel system. In the U.S., there are two types of emission standards; Federal and California. The U.S. Environmental Protection Agency (EPA) sets Federal emission standards and the California Air Resources Board (CARB) sets California standards. The vehicle regulations set by California have also been adopted by six New England states – New York, Massachusetts, Vermont, Connecticut, New Jersey, and Maine. Federal standards apply to all remaining states.

Both regulation programs have adopted the principle that vehicles doing the same job, carrying passengers, must meet the same emissions standards, regardless of the size of the vehicle or the fuel used. Today, most cars and light trucks meet multiple certification standards, for example, a California standard and a Federal standard. This allows automakers to sell their vehicles nationwide and satisfy both sets of emission regulations. Below is a brief introduction to the standards placed on 2004 and newer model year vehicles. Overall, the federal standards are really complicated for the average person to understand. The easiest standards to recognize are the Phase II Low-Emission Vehicle Standards, which are commonly used in vehicle showrooms across the nation.