The Trump administration has filed a lawsuit against California over a fuel economy rule that it claims is effectively creating a mandate for electric vehicles. The Department of Justice, representing the National Highway Traffic Safety Administration (NHTSA), filed the lawsuit on Thursday, alleging that California is imposing state-specific mileage requirements on car manufacturers through its Advanced Clean Cars proposal, in violation of federal law.
The legal battle is unfolding on two fronts – a challenge in the Ninth Circuit to overturn the revocations of emissions regulations and the DOJ lawsuit aiming to prevent California from enforcing underlying emission rules.
California Governor Gavin Newsom took advantage of the Advanced Clean Cars II regulations adopted by the California Air Resources Board (CARB) in 2022, which mandated an increasing percentage of new passenger and light truck sales to be zero-emissions, leading to 100% by 2035. President Biden’s EPA granted California a waiver to enforce this rule.
Newsom also supported other EV mandates such as Advanced Clean Trucks (ACT) and the Heavy-Duty Omnibus Law-NOx Regulation. These regulations have served as a model for several other states looking to surpass federal vehicle pollution standards.
The Trump administration argues that the strict emission standards imposed by California force automakers to produce vehicles with better gas mileage to comply, thus violating federal law.
In response to Trump revoking California’s emission regulations, Newsom issued an executive order for the development of Advanced Clean Cars III and offering preferential treatment to compliant car manufacturers. The legal battle continues with challenges to the CRA revocations and the DOJ lawsuit against California’s emission rules.
Transportation Secretary Sean Duffy expressed support for eliminating the EV mandate and allowing auto manufacturers to produce more affordable cars desired by American families. However, he criticized Newsom for persisting with the EV mandate despite its legality.

