The Environmental Protection Agency and the Department of Transportation have finalized standards for medium- and heavy-duty vehicles in an effort to improve fuel efficiency and cut carbon pollution.

The standards, which apply to trucks built in model years 2021-2027, are expected to lower carbon dioxide emissions by 1.1 billion metric tons, save vehicle owners $170 billion in fuel, and reduce oil consumption by up to 2 billion barrels over the lifetime of the vehicles sold.

Heavy-duty trucks account for about 20% of greenhouse gas emissions and oil use in the transportation sector, according to Environmental Protection Agency.

The standards apply to semi-trucks, large pickup trucks and vans, and all types and sizes of buses and work trucks.

And for the first time, the agencies are finalizing fuel-efficiency and greenhouse gas standards for trailers. Cost-effective technologies for trailers – including aerodynamic devices, lightweight construction and self-inflating tires – can significantly reduce total fuel consumption by tractor-trailers, while paying back the owners in less than two years due to the fuel saved.

Recognizing that many trailer manufacturers are small businesses, Environmental Protection Agency has included provisions that reduce burden, such as a one-year delay in initial standards for small businesses and simplified certification requirements.

Today’s final rulemaking builds on the fuel efficiency and emissions standards already in place for model years 2014-2018, which are expected to result in carbon dioxide emission reductions of 270 million metric tons and save vehicle owners more than $50 billion in fuel costs, according to Environmental Protection Agency. Truck sales were up in model years 2014 and 2015, the years covered under the first round of truck standards.

For more details on the new standards for medium- and heavy-duty vehicles, visit the EPA website.