BMW goes four-cylinder for fuel-sipping 2012 528i in U.S.!

The 2012 BMW 5-Series will be the automaker's first four-cylinder midsize sedan in North America.

BMW has sliced two cylinders from its entry-level 5-Series in the North America to create the most fuel-efficient midsize sedan it has ever offered this market.

The 2012 528i gains BMW's TwinPower four-cylinder gasoline engine, a 2.0-liter mill that takes the technology the automaker has gleaned from its 3.0-liter TwinPower engine (335i, 535i, among others) to create an ultra-efficient four-cylinder. It features a high-pressure direct injection system, BMW's unique Valvetronic intake control and a single twin-scroll turbocharger.

In the 528i, it boasts 240 horsepower and 260 lb-ft. of torque, figures that match (horsepower) and exceed (torque, by 30 lb-ft.) the current 3.0-liter naturally aspirated inline-six. Thanks to the twin-scroll turbocharger, BMW says that peak torque hits at just 1,250 rpm, about 1,500 rpm lower than the outgoing six-cylinder.

To save fuel, the 528i gains auto start/stop, which automatically shuts down the engine when the car is stationary at a stop light.

As a result, BMW says that the 0-60 mph sprint takes 6.2 seconds with the standard eight-speed automatic transmission, a 0.4 improvement over the 2011 model. The automaker also expects fuel economy to improve by up to 15 percent, meaning the EPA might rate the new car's combined fuel economy as high as 29 mpg. Look for a highway figure between 35 and 36 mpg.

Moreover, BMW will now offer the 528i with its xDrive all-wheel-drive system. Previously, the 528i offered only rear-wheel-drive in this market. BMW has not hinted what sort of a toll the all-wheel-drive will take on fuel economy.

Pricing has not been announced. The 528i will go on sale this fall in the U.S.