California and 22 other states filed a lawsuit in federal court Friday against the Trump administration, challenging its decision to revoke the most-populous state’s right to set pollution limits on cars and light trucks.
The legal battle’s outcome will affect which vehicles Americans drive in the years to come, as well as the country’s effort to tackle climate change and the balance between federal and state power.
The lawsuit is the latest salvo in the escalating legal and political fight between President Trump and California, which has created uncertainty and divisions in the auto industry. Both domestic and foreign automakers are grappling with which standards to follow as they prepare to manufacture vehicles for U.S. consumers over the next decade.
On Thursday, the Environmental Protection Agency and the Transportation Department formally revoked the waiver allowing California to set stricter limits on tailpipe emissions than the federal government, as part of a broader effort to scale back federal rules requiring U.S. auto fleets to average nearly 51 miles per gallon by model year 2025. Trump officials have drafted a plan to freeze federal mileage standards at roughly 37 miles per gallon though model year 2026.