Tough emissions standards worldwide and soaring manufacturing costs in Germany are behind BMW's decision to switch from high-revving, naturally aspirated engines in its M high-performance vehicles to turbocharged direct-injection powerplants, beginning as early as next year.

M3's 4.0-liter V8 and the M5's 5.0-liter V10 both engines will make way for forced-induction engines in coming years, according to high-ranking BMW sources.

The first M vehicle to make the move to the new turbo powerplants is the X6 xDrive M, which will challenge the Porsche Cayenne GTS and the Mercedes-Benz ML63 AMG. Set to appear next June, the X6 xDrive M will be the first model to run BMW M's new twin-turbocharged V8. This engine is also earmarked for the next-generation M5, due out in late 2010.

Based on the standard X6 xDrive 5.0i's 4.4-liter 90-degree V8, the new twin-turbo unit is said to match the current M5's naturally aspirated 5.0-liter V10 for power at 500 hp, while providing as much as 516 lb-ft of torque. This M-powered X6 should be enough to provide 0-100km/h acceleration of less than 5 seconds and top speed limited to 250 km/h.

Source: Autoweek