(Adds EPA, automaker reaction)
By David Shepardson
WASHINGTON, June 9 (Reuters) - New York State's attorney general and 12 other top state law enforcement officials said on Friday they would mount a vigorous court challenge to any effort to roll back vehicle emission rules by the Trump administration.
In March, President Donald Trump ordered a review of U.S. vehicle fuel-efficiency standards from 2022-2025 put in place by the Obama administration, saying they were too tough on the auto industry.
The push to weaken the rules by the Trump administration comes as automakers are worried that consumers shift to larger vehicles and low gas prices will make it expensive or impossible to meet the regulations. They also fear a prolonged fight with states over the rules could make revising their product plans difficult.
Democratic state officials have been increasingly aggressive in challenging Trump administration regulatory rollback efforts.
"In light of the critical public health and environmental benefits the standards will deliver, if EPA acts to weaken or delay the current standards for model years 2022-25, like California, we intend to vigorously pursue appropriate legal remedies to block such action," the state attorneys wrote in a letter to the Environmental Protection Agency including Pennsylvania, Connecticut, Massachusetts, Iowa, Washington State, Oregon and Rhode Island.
An EPA spokesman said Friday the agency is reviewing the letter.
Automakers including General Motors Co, Ford Motor Co and Toyota Motor Corp say the Obama administration did not conduct a proper review to ensure those rules are feasible.
Automakers have met with Trump administration officials in recent months and hope to reach a deal with California and other states on vehicle fuel efficiency standards.
Gloria Bergquist, a spokeswoman for the Alliance of Automobile Manufacturers, a trade group, said automakers "urge everyone to avoid pre-judging the results" of the ongoing review. "A process is now under way again for a thoughtful and coordinated analysis,"
California has opposed weakening the rules, threatened to pursue tougher standards unilaterally and could mount a legal challenge.
The White House plans to hold negotiations with car companies, California and potentially other states. A deal would remove uncertainty for automakers, who need years of lead time to engineer future models and want uniform rules across all 50 states.
The Obama administration's rules, negotiated with automakers in 2011, were aimed at doubling average fleet-wide fuel efficiency to 54.5 miles per gallon by 2025. Under the 2011 deal, the 2022-2025 model year rules had to be finalized by April 2018. The Obama administration completed a review of the 2022-2025 rules days before leaving office.
Without a deal, automakers could be forced to meet one set of standards in California and a dozen states that have adopted its rules and other rules in the rest of the country.
In 2011, Obama said the rules would save motorists $1.7 trillion in fuel costs over the life of the vehicles, but cost the auto industry about $200 billion over 13 years. (Reporting by David Shepardson; Editing by Chizu Nomiyama, Bernard Orr)