U.S. raising mileage mark

WASHINGTON – The Obama administration has finalized new fuel economy rules that will require the fleet-wide average of new cars and trucks sold in the U.S. to double over the next 13 years.

The average fuel economy must reach 54.5 miles per gallon by 2025, up from 28.6 mpg at the end of last year.

The regulations will bring dramatic changes to the cars and trucks in U.S. showrooms, with the goal of cutting greenhouse gas emissions and fuel consumption.

To meet the standard, automakers will need to introduce new technology to improve gasoline-powered engines. And they’ll need to sell more alternative fuel vehicles. Critics say the rules will add thousands to the price of new cars and make them unaffordable for many.

The administration says the latest changes will save families more than $1.7 trillion in fuel costs and bring an average savings of $8,000 over the lifetime of a new vehicle sold in 2025. The standards also are the biggest step the U.S. government has ever taken toward cutting greenhouse gas emissions, Environmental Protection Agency Administrator Lisa Jackson said. Tailpipe emissions from cars and light trucks will be halved by 2025, the government said.

President Barack Obama said the new fuel standards “represent the single most important step” his administration has taken to reduce U.S. dependence on foreign oil.

But Republican presidential candidate Mitt Romney has opposed the standards, and his campaign called them extreme and said they would drive up the price of new cars.

The gas mileage requirements will be phased in gradually and get tougher starting in 2017. They build on a 2009 deal between the Obama administration and automakers that committed cars and trucks to average 35.5 mpg by model year 2016.

Under the complex regulations, dubbed “Corporate Average Fuel Economy, or CAFE,” automakers can have lower mileage by using credits for selling natural gas and electric vehicles, changing air conditioning fluid to one that pollutes less, and even for placing louvers on car grilles to improve aerodynamics.

Still, automakers have been adding technology to boost gas mileage, mainly because people want to spend less on gasoline, which averaged about $3.75 per gallon this week.

By 2025, some bigger models may disappear, and dealers could offer more efficient gas-electric hybrids, natural gas vehicles and electric cars. There also will be smaller motors, lighter bodies and more devices to save fuel, such as circuits that temporarily shut off engines at traffic lights.