WASHINGTON — 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 heavy-duty trucks and buses to improve their fuel efficiency 5 percent each year between 2013 and 2018, compared with the industry’s 2010 baseline, which the administration estimates 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 its operating life.

Unlike recently announced fuel-efficiency standards for passenger cars and light trucks, which had prompted a contentious behind-the-scenes battle in Washington, the new regulations were welcomed by trucking industry officials.

“While we were working to improve the efficiency of cars and light-duty trucks, something interesting happened,” President Barack 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.”