washington new york state attorney general 12 top state law enforcement officials say friday would mount vigorous court challenge effort roll back vehicle emission rule trump administration march president donald trump order review u.s. vehicle fuel-efficiency standards 2022-2025 put place obama administration say tough auto industry push weaken rule trump administration come automakers worry consumers shift large vehicles low gas price make expensive impossible meet regulations also fear prolong fight state rule could make revise product plan difficult democratic state officials increasingly aggressive challenge trump administration regulatory rollback efforts light critical public health environmental benefit standards deliver epa act weaken delay current standards model years 2022-25 like california intend vigorously pursue appropriate legal remedy block action state attorneys write letter environmental protection agency include pennsylvania connecticut massachusetts iowa washington state oregon rhode island epa spokesman say friday agency review letter automakers include general motor co ford motor co toyota motor corp say obama administration conduct proper review ensure rule feasible automakers meet trump administration officials recent months hope reach deal california state vehicle fuel efficiency standards gloria bergquist spokeswoman alliance automobile manufacturers trade group say automakers urge everyone avoid pre-judging result ongoing review process way thoughtful coordinate analysis california oppose weaken rule threaten pursue tough standards unilaterally could mount legal challenge white house plan hold negotiations car company california potentially state deal would remove uncertainty automakers need years lead time engineer future model want uniform rule across 50 state obama administration rule negotiate automakers 2011 aim double average fleet-wide fuel efficiency 54.5 miles per gallon 2025 2011 deal 2022-2025 model year rule finalize april 2018. obama administration complete review 2022-2025 rule days leave office without deal automakers could force meet one set standards california dozen state adopt rule rule rest country 2011 obama say rule would save motorists 1.7 trillion fuel cost life vehicles cost auto industry 200 billion 13 years coalition 13 state challenge trump vehicle emission standards