Washington clean car standards

To protect public health, we set emission standards for vehicles registered in Washington. Vehicle pollution causes health problems, such as cancer and asthma, and also contributes to climate change.

Committed to cleaner vehicles

In 2005, the Legislature adopted the Clean Car Law, requiring new cars to comply with California vehicle emission standards starting in 2009. Since 1971, California has had a waiver under the federal Clean Air Act to set emission standards that are more protective than the national standards set by EPA. The federal Clean Air Act allows states to adopt the federal standards or California's standards. Washington is one of 14 states, plus the District of Columbia, that chooses to follow California’s lead.

In 2018, EPA proposed to weaken the national vehicle emission standards by freezing emission improvements for model years 2021 through 2025. In response, California updated its rules to uphold the more protective standards. In December 2018, we adopted a rule that keeps Washington in line with California, ensuring that vehicles sold in Washington continue to meet the more protective emission standards.

This rule includes cars and light-duty trucks. New vehicles that do not meet Washington's vehicle emission standards cannot be registered, licensed, rented, or sold here — even if they meet federal standards. It is your responsibility to make sure your car meets the state standards.

What do you have to do differently?

If you are buying a new car in Washington, you don't have to do anything — because dealers can only sell vehicles that meet California's (and Washington's) vehicle emission standards. If you buy a vehicle with less than 7,500 miles that doesn't meet the California and Washington standards, you can't register that vehicle in Washington. Used vehicles with more than 7,500 miles can be registered. 

Fourteen other states, including Oregon and California, have the same vehicle emission standards. If you buy a  2009 or newer model car in one of those states, it will meet state standards.