The administration’s fuel efficiency rules will cut greenhouse gas emissions and fuel use by everything from long-haul tractor-trailers to school buses over the next several years. (LM Otero/AP)

The Obama administration set the first-ever fuel-efficiency rules for heavy-duty trucks and buses Tuesday, a move that will cut greenhouse gas emissions and fuel use by everything from long-haul tractor-trailers to school buses over the next several years.

The regulations require fuel-efficiency improvements of as much as 23 percent by model year 2018, compared with the industry’s 2010 baseline. The administration estimates that the rules will save a total of $50 billion in fuel costs and 530 million barrels of oil during that period.

Heavy-duty trucks and buses account for 20 percent of the nation’s annual greenhouse gas emissions. Federal officials said the stricter limits will increase the cost of a tractor-trailer by $6,220 while saving $73,000 in fuel costs over the operating life.

The regulations were welcomed by trucking industry officials, a response unlike that received by recently announced fuel-efficiency standards for passenger cars and light trucks, which prompted a contentious behind-the-scenes battle in Washington.

“While we were working to improve the efficiency of cars and light-duty trucks, something interesting happened,” President Obama said in a statement. “We started getting letters asking that we do the same for medium and heavy-duty trucks. They were from the people who build, buy, and drive these trucks. And today, I’m proud to have the support of these companies as we announce the first-ever national policy to increase fuel efficiency and decrease greenhouse gas pollution from medium-and heavy-duty trucks.”

With this regulation, all classes of U.S. vehicles now must meet some fuel efficiency standard.

Before making the announcement, Obama met for a half-hour in the Roosevelt Room with more than a half-dozen industry representatives, including Bill Graves, president and chief executive of the American Trucking Associations, and Jed Mandel, president of the Engine Manufacturers Association.

“Everyone was sort of patting everyone else on the back,” Graves said in a phone interview, adding that his members are confident that they will be able to buy vehicles that meet the new requirements. “Everybody knows what the expectations are, and everyone has lead time to meet those expectations. . . . I honestly believe one of the reasons we the users have confidence in this rule is we know how competitive these truck manufacturers, engine manufacturers are.”

Industry officials predicted that they will meet the new standards without a problem. Douglas W. Stotlar, president and chief executive of the freight transportation company Con-way Inc., called it “a realistic solution that will ultimately help reduce greenhouse gas emissions and conserve natural resources by helping to increase the fuel efficiency of our industry.”

Tim Solso, chairman and chief executive of Cummins Inc., the world’s largest independent manufacturer of diesel engines, said, “Having a clear set of standards allows us to invest in technologies that we will use not only here in the United States but globally.”

Environmentalists also hailed the new rules — issued jointly by the Transportation Department and the Environmental Protection Agency — as a step forward in reducing the nation’s carbon output. Vickie Patton, general counsel for the Environmental Defense Fund, said in an e-mail that the U.S. fleet of trucks and buses “consumes nearly 2.5 million barrels of oil per day” and that the regulation would “cut climate pollution by 270 million metric tons.”

“U.S. engine makers in the heartland of our nation have world class products that will help break our addiction to foreign oil, save Americans hard earned money through more fuel efficient engines, cut dangerous pollution, and expand clean technology exports,” Patton wrote.

Under the new limits, fuel efficiency for one type of tractor-trailer — a big rig with a “high roof sleeper cab” — would improve about 23 percent by 2018, and average miles per gallon would rise from 6 to 7.2.

Drew Kodjak, executive director of the International Council on Clean Transportation, said in an interview that the rules were significant because “it’s the first time globally a country has set efficiency standards for the full heavy-duty vehicle.”

Japan set standards for heavy-duty truck engines in 2006 but did not address parts that included the vehicles’ transmission and tires.

Setting the next round of standards, which would probably cover the trailing equipment pulled behind the trucks, could prove more difficult. Graves said that truckers expect fuel savings from the new rules will make up for the higher cost of equipment within two to three years but that it will be harder when trailers are “added to the mix.”