The Obama administration on Tuesday unveiled new fuel efficiency standards for heavy-duty vehicles, which it said would both reduce carbon emissions and save drivers billions of dollars at the pump.

The standards, unveiled as President Barack Obama enters the last five months of his final term, apply to heavy duty vehicles which account for 20 percent of greenhouse gas emissions and oil use in the US transportation sector, according to the Environmental Protection Agency.

Tractor-trailers, delivery trucks and school buses will be forced to reduce carbon emissions by up to 25 percent by 2027. Heavy pickup trucks and vans will have to become 2.5 percent more efficient on average each year between 2021 and 2027.

The new standards will result in $170 billon in fuel savings over the lives of covered vehicles and encourage technical advances, according to the EPA and the National Highway Traffic Safety Administration.

The agencies said savings from meeting the new standards would offset the costs to truck owners to comply.

"This next phase of standards for heavy- and medium-duty vehicles will significantly reduce greenhouse gas emissions while driving innovation, and will ensure that the United States continues to lead the world in developing fuel-efficient technologies through the next decade and beyond," said EPA Administrator Gina McCarthy in a statement.

In an oblique reference to the emissions cheating scandal engulfing the German automaker Volkswagen -- which has admitted to configuring vehicles to deceive emissions tests -- the EPA announcement noted that the new policy would include improved test procedures and "protection against defeat devices."