US publication Autoweek spoke to unnamed high-ranking BMW officials and managed to dig out a confirmed plan to phase out the high-revving normally aspirated engines in the current BMW M cars and replace them with turbocharged motors based on the new 4.4 litre V8 engine that debuted in the BMW X6.

The first car to use the new turbocharged M engine will be the new BMW X6 xDrive M set to debut in June 2009. This vehicle will be positioned against other performance SUVs such as the Porsche Cayenne GTS and the Mercedes-Benz ML63 AMG. Power is expected to at least match the output of the 5.0 litre V10 from the M5, which means 500 horses and above.

BMW currently uses a range of inline-6, V8 and V10 high-revving motors in their M cars. The BMW Z4 M (the Z4 due to be replaced in the very near immediate future) uses a version of the high-revving inline-6 engine that was slotted into the E46 M3 while the M3 and M5 uses a high revving 4.0 litre V8 and 5.0 litre V10 respectively.

Some of the M5’s competitors are already on forced induction power. The new Audi RS6 uses a twin turbo V10 and while the W211 E63 AMG currently uses a normally aspirated 6.2 litre V8 engine, this is expected to be replaced by a turbocharged direct injection version for the W212 E-Class.