The White House says the standards the president was announcing will save businesses billions of dollars in fuel costs, help reduce oil consumption and cut air pollution. The standards apply to vehicle model years 2014 to 2018.
Senior administration officials said the new targets affect three categories of vehicles.
Big rigs or semis will have to slash fuel consumption and production of heat-trapping gases by up to 23 percent. Gasoline-powered heavy-duty pickups and vans will have to cut consumption by 10 percent, or by 15 percent if the vehicles run on diesel fuel.
The standards also prescribe a 9 percent reduction in fuel consumption and greenhouse gas emissions for work trucks, which include everything from fire trucks and concrete mixers to garbage trucks and buses, according to the officials, who requested anonymity to speak before the formal announcement. Obama was unveiling the standards at a trucking business in Virginia, a state crucial to his re-election hopes.
The officials projected savings of 530 million barrels of oil and $50 billion in fuel costs over the expected lives of the vehicles covered by the new standards, along with improved air quality and public health.
The administration released no miles-per-gallon equivalent for the new standards, saying that doing so would be confusing given the different categories of vehicles, the different types of vehicles in each category and the varying payloads that each one carries.
Officials did stress that the costs of making the trucks more fuel-efficient -- ranging from hundreds to thousands of dollars -- will be recouped through reduced fuel costs over the lifetime of the vehicles.
It's the second round of fuel efficiency standards in the past month.
Last month, Obama announced a deal with automakers to double overall fuel economy to 54.5 mpg by 2025, starting in model year 2017. Cars and light trucks now on the road average 27 mpg.
That followed a 2009 deal committing cars and trucks to averaging 35.5 mpg by model year 2016.
Obama won Virginia in the 2008 presidential election, dealing a blow to the GOP in what had been a solidly Republican South. He was the first Democrat since Lyndon Johnson in 1964 to win Virginia in a presidential race.
The state again will be a critical battleground in the 2012 presidential race.