Light-duty vehicle standards

Each new clean vehicle sold receives a credit value that varies depending on whether it’s a true ZEV versus a plug-in hybrid. The manufacturer can also claim additional environmental justice credits, which are created when ZEVs are sold at a low MSRP, sold at a discount to community carshare programs, or sold off lease to dealers offering financial assistance.

Advanced Clean Cars only applies to model year 2025. Under this regulation, each vehicle receives 1-4 credits. The credit percentage required for model year 2025 is 22%, which translates to roughly 8-10% of new light-duty vehicle sales. 

Under Advanced Clean Cars II, the credit system was simplified so that the credit requirement for each model year is roughly the same as the sales percentage requirement. Advanced Clean Cars II begins with model year 2026 and requires 35% of new light-duty vehicles sold in Washington to be ZEVs. The sales requirement rises 6-9% each year until we reach 100% in model year 2035. 

When we reach the 100% sales requirement, new light-duty vehicles made in model year 2035 or later that don't meet Washington’s standards won’t be able to be sold, registered, licensed, or rented within the state, even if they meet federal standards. Manufacturers can continue to sell plug-in hybrids, as long as they don't exceed 20% of all new vehicle sales. 

There are some exceptions depending on which vehicle you're looking at, such as military tactical vehicles and authorized emergency vehicles. See the WAC 173-423-060 for more details.

Manufacturers, as a group, are on track to exceed Advanced Clean Cars’ 2025 requirement that 8-9% of new light-duty vehicles sold in Washington must be electric or plug-in hybrid. In 2025, electric and plug-in hybrid vehicles made up ~20% of Washington’s new vehicle sales. Individual manufacturer performance varies.  

The sales requirement rises to 35% in 2026, when Advanced Clean Cars II takes effect, but manufacturers have already banked significant credits. The benefits of ZEVs, including lower fuel and maintenance costs, are driving strong demand in Washington. Manufacturers are incentivized to meet that demand, and Ecology is committed to supporting that work.

The table below shows credits generated by Washington’s 2024 model year sales which can be used to comply with Advanced Clean Cars and Advanced Clean Cars II. Manufacturers can use excess credits from previous model years to comply too.

Total light-duty vehicle credit bank for Advanced Clean Cars and Advanced Clean Cars II as of MY 2024 (10/01/2025)

Note: After 2025, any remaining credits will be converted into Advanced Clean Cars II credits.