Consumer Reports sent letters and a consumer petition to the leaders of General Motors, Toyota, Fiat Chrysler, Nissan, Subaru, Mazda, Hyundai, Kia, and Mitsubishi, calling on the companies to drop their legal attack against America’s Clean Air Act, and instead support Clean Car standards that help drivers save money on fuel and reduce air pollution.

75,364 consumers signed the Consumer Reports petition demanding these actions from automakers.

A Consumer Reports (CR) analysis finds that a full rollback of America’s Clean Car standards would increase the cost of owning a new vehicle by $3,300 by 2025, and cost American consumers about $460 billion in total. Even a partial rollback could add $2,100 in net costs per vehicle.

If these companies are committed to a zero-emission future, they should support rules that have been proven to encourage technological innovation. Today’s vehicles are safer, more reliable, and more efficient than at any point in history, thanks to the strong program in place today. The current rules and state authority help protect consumers and reduce pollution. Undoing the standards would threaten this progress and the future fuel savings for drivers. —Shannon Baker-Branstetter, CR’s Manager of Cars & Energy Policy

Four major automakers—Ford, Honda, BMW, and Volkswagen—have agreed to a voluntary framework to continue making cars that produce less pollution and cost less to drive as well. These companies acknowledge that the technology to improve vehicle efficiency and reduce emissions already exists, and that automakers have a responsibility to deliver these improvements to customers.

On Tuesday, Bloomberg reported that the Trump administration has dialed back its plan to relax fuel-economy requirements for new automobiles, retreating from a bid to freeze the mandates for six years.

The Environmental Protection Agency and National Highway Traffic Safety Administration (NHTSA) originally proposed capping mileage and tailpipe greenhouse gas emission requirements after the 2020 model year, thwarting scheduled increases charted under the Obama administration. However, according tomthe bloomberg report, the agencies are now planning to require annual 1.5% increases in the stringency of those requirements for 2021-2026 vehicle fleets.

In a statement issued after the Bloomberg report surfaced, the Sierra club noted that “The reported change is still a far departure from the 5% annual increases set by the clean car standards today and a dangerous step backwards if finalized (the draft rule is still under review). Any attempt to weaken the standards drives us backwards on climate progress at a time when transportation makes up the single largest source of carbon emissions in the country.”