U.S. Senate Minority Leader Chuck Schumer and 11 other Democrats said on Tuesday it was "critical" that the Trump administration leave in place new vehicle fuel efficiency rules, saying the higher standards were achievable.
Scott Pruitt, the head of the Environmental Protection Agency, is expected to announce as early as this week the reopening of a review of the rules that were set by the Obama administration for the 2022-2025 period.
Automakers say the changes, which would raise the fleet average fuel efficiency to more than 50 miles per gallon by 2025 from 27.5 mpg in 2010, will impose significant costs and are out of step with consumer preferences. They argue they need more flexibility to meet the rules amid low gas prices.
Environmentalists, who favor the new standards, say they would reduce fuel costs and greenhouse gases and have vowed to sue if the Trump administration weakens them.
"These automobile emissions standards are economically feasible and technologically achievable for the auto industry," the Democratic senators wrote in a letter to Pruitt. "It is critical that they remain in place."
EPA spokeswoman Cathy Milbourn declined to comment on the letter "since the agency has not announced how it will proceed on the vehicle emission standards." The White House did not immediately respond to a request for comment.
Trade groups representing automakers including General Motors, Ford Motor and Toyota Motor have asked the EPA to withdraw the rules, which stem from a 2011 deal the industry reached with the U.S. government.
The chief executives of GM, Ford, and Fiat Chrysler Automobiles NV, along with the top North American executives at Toyota, Volkswagen, Honda, Hyundai Motor and others separately have urged President Donald Trump to revisit the decision.
The Obama administration in 2011 said the changes would save motorists $1.7 trillion in fuel costs over the life of the vehicles and cost the auto industry only about $200 billion over 13 years.
In July, the EPA estimated the fleet would average 50.8-52.6 mpg in 2025 because Americans were buying more SUVs and trucks. It had until April 2018 to decide whether the standards were feasible under a "midterm review," but moved up its decision to a week before President Barack Obama left office.
The EPA is also considering taking steps to reverse California's waiver under the Clean Air Act that allows it to set its own vehicle greenhouse gas emissions standards. California has repeatedly vowed to vigorously contest any efforts to withdraw its authority, and in January it hired former U.S. Attorney General Eric Holder to represent it.