Government sets strict fuel-economy goal of 54.5 by 2025

— -- Strict new federal fuel-economy and carbon-emission standards made final Tuesday are the biggest technological challenge to the auto industry since the government began regulating emissions in 1970 and mileage in 1975.

The rule sets the equivalent of 54.5 miles per gallon as the average the auto industry must achieve by 2025, up from 29.7 mpg now and 35.5 mpg in 2016.

The tough "CAFE" standard (for corporate average fuel economy), which was to be announced earlier this month, was announced Tuesday by the Obama administration on the day that Republicans' national convention got underway in Tampa.

It is "a monumental day for the American people," Transportation Secretary Ray LaHood said in announcing the final rules.

And it's the script for a likewise monumental change in the cars and trucks Americans drive. The vehicles will undergo more urgent evolution of current trends so that, in a decade or so, the American streetscape could resemble science fiction, including:

•More gas-electric hybrids and plug-in hybrids. More electric cars. A few that run on natural gas. Maybe a few more hydrogen-fueled cars.

•Smaller cars powered by smaller gasoline engines, most using turbochargers to get back the power they lose as they give up size.

•Dashboards that resemble video games, giving you colorful "atta-boys" when you drive with a light foot.

•More parts made from composites and high-price aluminum, titanium and high-strength steel — metals which have the additional hidden cost of wearing out fabrication equipment in auto assembly plants faster than conventional steel.

•Oval car bodies to slice the air. Sophisticated, many-speed transmissions and CVTs (continuously variable automatic transmissions) that can keep the engines running in their sweet spots where they make the most power on the least fuel.

Will car buyers embrace the new vehicles? "The risk is pushing technological demands beyond the automakers' ability to deliver. The smarter way to approach it is to let the market guide vehicle fuel-efficiency standards," says Jeremy Anwyl, vice chairman at auto-shopping site Edmunds.com.

"Consumers have shown a willingness to buy fuel-efficient cars," he says, "but not at the expense of other features on their checklists like comfort, space and performance. CAFE risks requiring automakers to build vehicles and adopt technologies that consumers may not want to buy."

Price and payback

And then there is the question of price. LaHood said that all the higher tech needed to meet the target will make a car $1,800 more expensive in 2025 than it otherwise would be. But its fuel-sipping ways should save $8,000 over the lifetime of the vehicle, he said.

The National Automobile Dealers Association (NADA) said it used the government's own figures to calculate a price increase of $3,000 per car, and noted that a vehicle's lifetime is more than 200,000 miles, meaning the fuel-cost savings won't likely all go to the person who paid the higher sticker price for the new car or truck.

The Natural Resources Defense Council, an environmental advocacy group, applauded the final rules.

"We're very happy. This is a good rule, a strong rule. This is the biggest step this country's taken to reduce pollution and our dependence on oil since the original 1970s" federal regulations, says Roland Hwang, NRDC's transportation director.