A 16-Year-Old Gasoline-Ethanol Feud Gets Supreme Court Showdown

A long-running clash between gasoline and ethanol producers will be before the U.S. Supreme Court on Tuesday, in a case that could cost small oil refineries hundreds of millions of dollars.

At issue is the ability of refineries to win exemptions from 16-year-old U.S. government mandates that they mix renewable fuels into gasoline and diesel.

Under former President Donald Trump, the Environmental Protection Agency let dozens of small refineries off the hook. Though the Biden administration is set to change course, a high court ruling limiting refinery waivers would remove its discretion.

Such a ruling could reverberate for years, ...