Trump Wants to Trade Fuel Economy for Cheaper Cars. But It Might Not Work

By rolling back auto industry fuel efficiency goals, US president Donald Trump hopes to make new cars cheaper. But prices won't drop for years, and consumers will spend more on gas in the meantime.

The Trump administration says its proposal to roll back vehicle fuel economy standards, announced officially in the Oval Office on Wednesday, is an attempt to shave dollars off the ballooning cost of new cars in the US.

But the intended price drops likely won’t show up on dealership lots and showroom floors for months if not years, given the length of automakers’ product planning schedule. It would also likely force Americans to pay more, long-term, at another place they tend to visit more frequently: the pump.

The proposal from the US Department of Transportation would require automakers to reach a fleet-wide average of 34.5 miles per gallon by model year 2031, down from ...