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Transportation is the largest source of carbon pollution in Washington. Transportation contributes about 22% of total air pollution and 39% of greenhouse gas emissions throughout the state. Vehicle pollution causes health problems, such as cancer and asthma, and also contributes to climate change.
In 2020, the Motor Vehicle Emission Standards law directed us to adopt California vehicle emission standards. In Nov. 2021, we adopted the zero emission vehicle standards that require a percentage of the vehicles sold in Washington to be zero emission, starting with the 2025 model year. Consumers will have more choices of zero emission vehicle models, from light-duty cars and trucks to medium- and heavy-duty trucks.
In Dec. 2022, we adopted California's vehicle emissions standards. The Clean Vehicles Program rule increases zero emission vehicle sales of passenger cars, light-duty trucks, and medium-duty vehicles to 100% starting in 2035. It also requires cleaner burning engines in medium- and heavy-duty trucks.
For a new vehicle to meet Washington's standards, it must be California, or 50-state certified. Check the emission label found under the hood.
The amount of pollution a car puts into the air depends mainly on which emission standards it meets. It can also be affected by how you drive and maintain the car, how much fuel the car uses, and the kind of fuel used.
Passenger cars must meet certain fuel mileage standards. Generally, the better the fuel mileage, the “cleaner” the car. For example, smaller cars typically get the best fuel mileage, which also means they pollute less.
Light trucks — which include vans, small pickup trucks, and sport utility vehicles (SUVs) — are allowed to get lower fuel mileage than passenger cars. As a result, the average light truck pollutes more than the average car.
Use this searchto view and compare clean cars you can buy.
Clean driving tips
Keep your car well maintained — A poorly-maintained engine creates more air pollution and uses more fuel. Replace oil and air filters regularly. Keep your tires properly inflated.
Drive less — Carpool, walk, bike, ride the bus, or work from home to save money as well as reduce air pollution.
Don’t idle your vehicle — If you stop for more than 30 seconds, except in traffic, turn off your engine. Idling for a total of 10 minutes a day uses an average of about 22 gallons of gas per year, and pollutes the air. By turning your engine off when it isn’t moving, you’ll save money on gas. Additionally, you, and others around you, won't have to breathe unhealthy exhaust fumes.
Don’t buy more car than you need — Four-wheel drive, all-wheel drive, engine size, vehicle weight, and tire size all affect the amount of fuel your vehicle uses. The more fuel it uses, the more air pollution it causes.
The Legislature passed this law to reduce air pollution and greenhouse gases from cars and trucks. More than half of Washington's residents have at least one medical condition that is made worse by air pollution. Pollution from vehicle exhaust causes health problems, such as cancer and asthma, and contributes to climate change.
Motor vehicles and other types of transportation emit nearly half of the greenhouse gas emissions in Washington. These greenhouse gases cause climate change. The effects of climate change in Washington include reduced snow pack, low summer stream flows, more winter flooding, sea level rise, less water for people and agriculture, further loss of salmon habitat, and dangerous wildfires.
The Environmental Performance (EP) label is displayed on new vehicles for sale. The label provides greenhouse gas and smog emissions scores. The scoring system allows consumers to compare the vehicle’s greenhouse gas and smog emissions to other models. People can then make more informed decisions that include climate change impacts when buying a vehicle.
