BMW announced that its 528i sedan will drop its current inline six-cylinder engine in favor of a twin-turbo 2.0-liter four-cylinder for 2012. With 240 horsepower and 260 pound-feet of torque, the 2.0-liter engine offers identical power and an additional 30 lb-ft of torque compared to the 3.0-liter engine in the outgoing 2011 BMW 528i. BMW says the turbo four hits its horsepower peak at 5,000 rpm and reaches peak torque at a remarkably low 1,250 rpm.

The new 2.0 turbo unit will be mated to an eight-speed automatic transmission only. BMW says the 2012 528i will sprint from 0 to 60 mph in 6.2 seconds, 0.4 second quicker than the 2011 model. Also new for the 2012 528i is a standard start/stop system which switches off the engine when the car is stationary at traffic lights to minimize fuel consumption. BMW says the revised 528i is some 15 percent more fuel efficient than the outgoing model.

BMW's xDrive all-wheel-drive system will also be an available option on the 528i for 2012. Currently, all-wheel drive is only available on 535i and 550i models. BMW is betting that added power and efficiency will be enough to overcome the idea of a four-cylinder 5 Series.

In related news, 2012 sees the return of the 520i model, powered by a 2.0 litre petrol engine with TwinPower Turbo technology as well. In this application, it generates 181 hp and 270Nm of torque, propelling the sedan from 0 to 100km/h in 7.9 seconds before reaching a top speed of 227km/h. The closest rival to the upcoming 520i would be the Mercedes Benz E 200 CGI. The 520i completes the century sprint faster than the E 200 by 0.3 seconds but will incur a slightly higher road tax due to its additional 200cc over the E 200's 1.8 litre engine.