BMW's new M-powered versions of the X6 will be the first car to get a new turbocharged direct-injection V8 as the firm begins to move away from high-revving, naturally aspirated engines for its high-performance models.
Increasingly tough emission standards and soaring manufacturing costs have pushed BMW into the decision, which could alter the intrinsic character of all BMW M models.
The future of the 4.0-litre V8 in the BMW M3's and the 5.0-litre V10 BMW M5 is unclear, as both will make way for forced-induction engines, well placed Munich insiders have said.
The M-badged X6, which will be called xDrive M, is due in June. Its twin-turbo V8 is also earmarked for the next-generation M5, due in 2010.
Based on the X6 xDrive50i's 4.4-litre V8, the new unit is said to virtually match the existing BMW M5's V10 for power, at 500bhp, while providing much more torque - up to 516lb ft.
This should be enough to provide the top-of-the-line X6 with 0-62mph acceleration in less than five seconds.