US President Barack Obama has announced tough targets for new fuel-efficient vehicles in order to cut pollution and lower dependence on oil imports.
Obama said the country's first-ever national standards would reduce vehicle emissions by about a third by 2016, reported BBC News.
The plan aims to replace overlapping rules on emissions and efficiency set by federal agencies and states.
Under the proposed standards, manufacturers would be required to begin improving fuel efficiency by 5% a year from 2012.
By 2016, they would have to reach an average of 39 miles per US gallon for passenger cars, and 30 miles per gallon for light lorries.
The new standards are expected to raise the price of new vehicles by about $1,300 (£839) per vehicle by 2016.
But the president said this would be offset by lower fuel cost within three years.
The proposed nationwide standard for exhaust emissions is expected to cut the amount of carbon dioxide produced by new passenger vehicles by 34%.