Major automakers are siding with the EPA in a court battle over tougher emissions standards, Reuters reported Wednesday.

Texas and 15 other states, along with ethanol groups, have challenged the EPA's emissions rules under the Biden administration, which aim to reinstate tougher rules after a rollback by the previous administration.

The Alliance for Automotive Innovation, a trade group representing most automakers selling cars in the United States, said in a court filing that the EPA rules "will challenge the industry" but provide automakers with "critically important flexibilities."

Big square baler harvesting wheat straw for production of cellulosic ethanol

Big square baler harvesting wheat straw for production of cellulosic ethanol

The group also said its members want to ensure that "critical regulatory provisions supporting electric vehicle technology are maintained."

That's a significant show of support from automakers considering the plaintiffs' argument in the case centers around the EPA allegedly forcing automaker to produce electric cars. Stricter emissions effectively favor battery-electric powertrains over internal combustion, and the EPA can't show favor to one technology over another, they claim.

The automakers are presenting a more united front than they did in the legal battle over California's ability to set its own emissions standards, fought between the state and the Trump administration.

2022 Ford F-150 Lightning Pro

2022 Ford F-150 Lightning Pro

In 2020, a set of automakers stepped up to back California, amid a challenge over its Clean Air Act authority, but several others, including General Motors, Fiat Chrysler Automobiles (now Stellantis), and Toyota weren't among them. Despite, in GM's case at least, apparent reputation damage, opposition continued until after Trump was out of office.

The Biden administration just earlier this week reinstated steeper fines related to Corporate Average Fuel Economy (CAFE) compliance. But a glut of credits will help assure easy compliance, a 2021 EPA report suggested.