



America’s cars run partly on fuels derived from corn and soy. That’s because of a decade-old federal mandate beloved by Midwestern farmers but opposed by an unusual coalition of oil refiners and environmentalists.

On Thursday, the Trump administration sided with the farmers and announced that it would stick closely to the current rules and quotas for fuel: Refineries must blend about 20 billion gallons of biofuel — much of it ethanol made from corn — into the nation’s gasoline supply, a level largely unchanged from last year.

The decision is a rare setback for the oil industry under a presidency that has filled its ranks with fossil fuel advocates and embarked on a rollback of rules aimed at reducing the industry’s regulatory obligations.

A number of environmental and health groups oppose the mandate, citing emerging research showing that ethanol is no cleaner than gasoline.