Autoblog

BMW may begin straying from its long held tradition of equipping its M models with rev-happy, naturally aspirated engines. According to a source speaking with Automotive News, the twin-turbocharged 4.4-liter V8 currently equipped on the new X6, could be stroked out to 4.8-liters and fitted on future Ms, including the new M5, due out in 2011. The twin-turbo'd 3.0-liter inline six found in the 335i, 535i and entry-level X6 proved that BMW has the chops to create highly efficient and eminently entertaining blown mills, and there's no doubt that significant tweaks to the turbocharged V8 could boost power levels over the stock mill's claimed 407 hp, to take take serious aim at Audi's 572 hp RS6.

[Source: Automotive News – Sub. Req.]

It's no surprise that BMW plans to attempt to bring its uber-saloon up to AMG-levels of power when the new M5 debuts in 2011. That means that output needs to surpass the current model's paltry 501 hp, so BMW will bore out the current V10 to 5.5-liters, slap on a couple of turbos and use direct-injection to bringing power levels up to 550 hp, or more. Grunt will be shoveled to the rear wheels via either a six-speed manual transmission or the new seven-speed M DCT dual-clutch 'box.

But it's not all about pavement-pummeling power. The use of the twin-turbochargers and DI is as much an attempt to reduce emissions as it is to boost output, and BMW is intent on making the next 5-series, due out in 2010, one of its most fuel-efficient vehicles. That means that start-stop technology will be used on the engine, along with its Efficient Dynamics system that uses regenerative braking to reduce load on the alternator, improving both fuel economy and engine output.

[Source: Autocar]