WASHINGTON — The Obama administration and the auto industry are locked in negotiations over new vehicle mileage and emissions standards that will have a profound effect on the cars Americans drive and the health of the auto industry over the next decade and beyond.

Depending on the stringency of the standard, the deal could also reduce global warming emissions by millions of tons a year and cut oil imports by billions of barrels over the life of the program, cornerstones of President Obama’s energy policy.

The administration is proposing regulations that will require new American cars and trucks to attain an average of as much as 56.2 miles per gallon by 2025, roughly double the current level. That would require increases in fuel efficiency of nearly 5 percent a year from 2017 to 2025.

The standard would put domestic vehicle fuel efficiency on a par with that in Europe, China and Japan, saving consumers billions of dollars at the pump and creating for the first time a truly global automobile market.