California EV Mandate Targeted in New Federal Lawsuit

USDOT and DOJ File Lawsuit Against California EV Mandate

Federal Lawsuit Targets California EV Mandate

The U.S. Department of Transportation and the U.S. Department of Justice have filed a lawsuit against the State of California. The case challenges vehicle rules that federal officials say act as an EV mandate.

The lawsuit was filed in the U.S. District Court for the Eastern District of California. It targets the California Air Resources Board (CARB) and its executive officer, Steven S. Cliff. Federal officials say California’s rules conflict with federal law that governs vehicle fuel economy standards.

The case is titled United States of America et al. v. California Air Resources Board. The case number is 2:26-450.

Federal agencies say California’s regulations impose requirements that function like fuel economy rules. Because of that, they argue the state’s EV mandate should not be allowed under federal law.

Federal Law Governs Fuel Economy and the EV Mandate Debate

The lawsuit centers on the Energy Policy and Conservation Act (EPCA). This federal law requires the National Highway Traffic Safety Administration (NHTSA) to set national fuel economy standards.

According to the complaint filed in the case, Congress created the law to ensure that the United States has a single national system for fuel economy rules.

The law prevents states from adopting regulations related to fuel economy when federal standards already exist.

Federal officials argue that California’s EV mandate is tied directly to fuel economy because the rules limit tailpipe carbon dioxide emissions. Carbon dioxide emissions and fuel consumption are closely linked.

When a vehicle burns less fuel, it produces less carbon dioxide. Because of this relationship, federal officials say regulations that limit CO₂ emissions are effectively regulations about fuel economy.

California Advanced Clean Cars Rules

The lawsuit focuses on California’s Advanced Clean Cars (ACC) regulations. These rules set limits on greenhouse gas emissions for passenger cars and light-duty trucks.

The regulations also require that a certain share of vehicles sold in California produce zero tailpipe emissions. Federal officials say this requirement functions as an EV mandate.

Manufacturers must show each year that their vehicles meet California’s emission targets. The rules apply to passenger vehicles and light-duty trucks sold in the state.

If manufacturers fail to meet the state’s standards, they may face civil penalties.

The regulations also require a growing share of vehicles sold each year to be zero-emission vehicles. For the 2025 model year, the rule requires 22 percent of vehicles sold in California to be zero-emission vehicles.

Federal officials argue that the EV mandate changes how automakers design and sell vehicles across the country.

Federal Government Seeks to Block California’s Mandate

In the lawsuit, the federal government asks the court to block California’s regulations.

The complaint asks the court to declare the state’s carbon dioxide emission standards unlawful. It also asks the court to stop California from enforcing those rules.

Federal officials are also seeking to invalidate the state’s EV mandate, which requires automakers to sell a certain percentage of zero-emission vehicles.

The government also asks the court to prevent California from adopting similar rules in the future.

Federal officials argue that different state rules could create a patchwork of regulations across the country. They say this could force manufacturers to design vehicles around California’s policies rather than national standards.

“Freedom Means Affordable Cars” Initiative

The lawsuit is part of a broader policy effort announced by the Trump Administration called “Freedom Means Affordable Cars.”

The proposal would reset the federal government’s Corporate Average Fuel Economy (CAFE) standards. These standards set fuel economy targets for passenger vehicles sold in the United States.

Federal officials estimate the proposal could save American consumers about $109 billion over the next five years.

Officials also estimate the proposal could lower the average cost of a new vehicle by about $1,000.

The proposal would adjust fuel economy standards for vehicles built between model years 2022 and 2031. The rule would gradually increase fuel economy targets during those years.

Federal officials estimate the proposal would result in a fleet average fuel economy of 34.5 miles per gallon by model year 2031.

The proposal would also eliminate the CAFE credit trading program beginning in model year 2028.

Possible Impact of the EV Mandate Case on Trucking

The lawsuit focuses mainly on passenger cars and light-duty trucks. However, the outcome of the EV mandate case could affect the broader transportation industry.

Automakers often build vehicles for the entire U.S. market. If states enforce different vehicle standards, manufacturers may need to redesign vehicles or adjust production plans.

This could affect vehicle prices and the pace of technology changes.

For trucking companies and commercial fleets, the case may influence future debates about vehicle emissions rules and fuel economy standards.

Similar discussions are already taking place about emissions rules for medium- and heavy-duty trucks.

Court Battle Continues

Federal officials argue that California’s EV mandate violates federal law and interferes with the national fuel economy system.

California officials have previously argued that their emissions rules are allowed under environmental laws that permit stricter state standards in some cases.

The case will now move through the federal court system. The decision could determine whether California can continue enforcing its current vehicle emissions rules.

The ruling could also shape how vehicle regulations are set across the United States in the years ahead.