US carmakers may seek changes to federal fuel-economy rules

Detroit

SINCE agreeing to tough new federal fuel-economy standards five years ago, carmakers have been methodically improving the petrol mileage of their vehicles and reducing emissions harmful to the environment.

But despite investing billions in fuel-saving technologies and introducing a raft of lower-mileage models and electric cars, the industry will be hard-pressed to meet its target of 54.5 mpg (miles per gallon) in 2025.