The head of BMW's M division, Ludwig Willisch, recently released news that the performance division is working on a high-performance X5. Although the M's mantra is to increase performance through weight shedding, the increasingly popular sport SUV market has made it impossible for BMW to resist designing an M version of the popular X5, especially considering the successes of rivals Porsche and AMG of Mercedes-Benz in selling their respective Cayenne and ML performance SUVs.
Recent photos were snapped at BMW's South Carolina test track, showing an X5 that was aggressively styled, yet was still subtle enough to show its classic X5 styling, similar to a previously spotted X5 model from late 2007. The X5 M test car sported quad exhaust pipes, which may be an indication of a higher-performing engine compared with the regular X5's 4.8L V-8. Other details suggesting a new powertrain was a warning message spotted within the X5's cabin reminding test drivers to turn the engine off after 30 minutes or risk engine failure.
The two popular suggestions for the possible powertrain are the naturally-aspirated 5.0L V-10 from the M5, and the twin-turbo 4.4L V-8 from the X6. With rising fuel costs and a previous BMW release stating that the 5.0L V-10 would be reserved only for the M5 and M6, it looks most likely the 4.4L V-8 will be used in the X5 M.
Source: Motor Authority