BMW revives four-cylinders for better mileage

BMW is bringing four-cylinder engines back to the U.S. market as one response to the scheduled increase in fuel-economy regulations.

BMW quit selling the four-cylinders for its 3-series lineup in 1999 because of low demand, but gasoline cost only $1.14 per gallon at the time.

BMW says the return of the smaller engines won't cost customers any power.

"It wasn't in line with our image, because it didn't have the performance of the six-cylinder," BMW's U.S. chief, Jim O'Donnell, told Bloomberg. "Now that the engines have developed so far, it's not an issue at all."

BMW plans to offer a four-cylinder in the Z4 roadster and the 3-series, set to arrive at U.S. dealerships this October.

The U.S. corporate average fuel economy requirement is increasing from 27.5 mpg in 2010 to 30.1 mpg this year, according to the U.S. Environmental Protection Agency. By 2016, it will have risen to 35.5 mpg. By 2025, it is estimated to reach 54.5 mpg.

By Michelle Koueiter