Federal court strikes down EPA fuel economy rule

The U.S. Court of Appeals for the Fifth Circuit ruled this week in favor of Texas Corn Producers, Texas Sorghum Producers, and National Sorghum Producers, vacating a 2024 Environmental Protection Agency rule that they said unfairly penalized ethanol-containing fuels in federal fuel economy calculations.

At issue was the EPA’s use of an “R Factor” — a technical value automakers must use when certifying the fuel economy of new vehicles. Under the previous administration, the EPA implemented a new R Factor for E10 (gasoline blended with 10 percent ethanol) in 2024 — replacing decades of testing based on E0 (pure gasoline). However, the court found that the EPA’s value for E10 was set “arbitrarily low” and relied on flawed science, thereby reducing automakers’ fuel economy ratings for ethanol blends and creating a backdoor penalty on ethanol.

“This is a meaningful win for America’s sorghum and corn producers, and we want to thank all those that helped us achieve this win,” National Sorghum Producers CEO Tim Lust said. “The court’s ruling restores fairness and transparency to how ethanol is treated in fuel economy rules and holds the government accountable to sound science.”

In its decision, the court criticized the EPA’s “half-hearted defense” of the rule as “lipstick on a pig,” concluding the agency “identifies no evidence to support [its] ‘trust-us-we’re-the-experts’ response.” The ruling requires the EPA to go back to the drawing board and establish a new, evidence-based R Factor for E10 fuel.

“Ethanol is a cleaner, American-grown solution to reducing transportation emissions,” Texas Corn Producers Executive Director David Gibson said. “This ruling ensures ethanol isn’t penalized by flawed methodology, and it gives the current EPA administration a fresh opportunity to get this right.”

“The court affirmed what growers have long said, that the science matters, and so does the way agencies engage with it,” added Wayne Cleveland, Executive Director of Texas Sorghum Producers. “We’re optimistic that this new chapter will lead to better policy and a level playing field for biofuels.”

The Fifth Circuit’s decision clears the way for the current EPA to revise the regulation using accurate, representative data. For ethanol producers and the farmers who supply the industry, the ruling protects access to fuel markets and supports a more sustainable, domestically sourced energy future.