What State Has The Strictest Emissions Regulations?

The Environmental Protection Agency (EPA), enforces clean air practices throughout the United States, but the federal government has given the state of California special dispensation to set its own emission standards for automobiles. As a result, the state of California has set the strictest emission regulations in the country, which are being slowly adopted by other states. Automobile emission regulations in California have been credited by carmakers and environmentalists for promoting the development of vehicles that emit less pollution.

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Its been estimated by the State Air Resources Board that new cars sold in California are running up to 10 times cleaner than cars that were sold 20 years ago. That number is very impressive because in that time there was a 50% increase in cars in the state, with more than a 65% increase in the miles driven every year. As a result, emissions from cars in California have substantially dropped, setting the standard for emission control in the country as a whole.

California is the place where many major technological advances in pollution control for cars, like the catalytic converter, were first introduced. That follows a pattern where emissions control technology is first developed in California and is then distributed throughout the country.


Tougher Emissions Standards in California

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The state of California isn’t content with already having the strictest emissions regulations in the country, they plan on introducing tougher emission standards to counter global climate change. Those standards are set to be adopted by at least 8 Northeastern states. A proposal to reduce hydrocarbon emissions was approved recently, which is a major contributor to smog. Strict regulations for other automobile pollutants like nitrous oxide are also being phased in.

On top of that California is also going to introduce the requirement of cars meeting emission standards for 100,000 miles, which is an increase from the previous 50,000-mile standard. The reason being that emissions tend to increase when the vehicle starts aging. The emissions standards in California are stricter than the standards set by the federal EPA, with heavy requirements on older construction vehicles to ensure they run cleaner.




California has established several categories for automobile emissions, which include the following:

  • ZEV – Zero Emission Vehicle: These automobiles don’t have tailpipe emissions, and cars you’ll find in this category are hydrogen fuel cell vehicles and plug-in electric cars.
  • SULEV – Super Ultra Low Emissions Vehicle: These cars have emissions that are 90% cleaner than your average new automobile.
  • PZEV – Partial Zero Emission Vehicle: These automobiles have zero evaporative emissions but must meet the same emissions regulations as the SULEV automobiles.
  • ULEV – Ultra Low Emission Vehicle: These automobiles have emissions that are 50% cleaner than your average new automobile.
  • LEV – Low Emission Vehicle: Any automobile that is sold in California after 2004 must meet LEV standards or better than that.


We appreciate and admire California’s dedication to a cleaner planet and ecosystem of its residents!

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