Car manufacturers in the US passed the tougher standards for greenhouse gas emissions last year.
They have been met for the third year running, according to the Environmental Protection Agency (EPA).
It states manufacturers are “over complying” with the emission standards by 13 grams of CO2 per mile or around 1.4 miles per gallon.
EPA estimates they have resulted in reducing emissions by roughly 60 million metric tons of CO2 – equivalent to the amount emitted from electricity use by more than eight million homes annually.
It claims US consumers who buy a new Model Year 2025 car will save more than $8,000 (£5,404) in lifetime fuel costs as a result of the standards.
The programme in total is expected to help save $1.7 trillion (£1m) in fuel costs, reduce the nation’s fuel usage by 12 billion barrels of oil and cut greenhouse gas emissions by six billion metric tons.
Christopher Grundler, EPA’s Director of the Office of Air Quality and Transportation said: “For the third year in a row, manufacturers have exceeded the GHG emissions standards by a wide margin. It’s clear that our standards are working, spurring technology and innovation and we are on track to achieve significant greenhouse gas reductions.”
Earlier this year Volkswagen admitted to using a software to falsify car emissions following which EU governments agreed to using a more realistic approach to test emissions. The standards were however rejected by the European Parliament’s Environment Committee this month.