“Obama Sets New Auto Emissions and Mileage Rules”:

The rules, which will begin to take effect in 2012, will put in place a federal standard for fuel efficiency that is as tough as the California program, while imposing the first-ever limits on climate-altering gases from cars and trucks.

The effect will be a single new national standard that will create a car and light truck fleet in the United States that is almost 40 percent cleaner and more fuel-efficient by 2016 than it is today, with an average of 35.5 miles per gallon.

NPR reports:

The White House said the cost of building more fuel efficient vehicles would increase their cost by about $1,300, but “even as the cost of building these cars and trucks goes up, the cost of running them will go down,” the president said.

Within three years, the fuel savings would make up for the bigger price tag, he said.