After starting the engine, I expected something more M3-like but the sound is even worse than on the Cayenne Turbo S. There is a light growl when you accelerate from standstill but nothing V8-like and it disappears and gets a much higher pitch once you pass 3000 rpm. To make it short: very disappointing exhaust/engine sound, the X6 M sounds like a X6 Diesel or even worse, like a 4-cylinder hatchback. There is definetely nothing "M" about the exhaust/engine sound on the X6 M.

 

 

Ouch ! Not good news for the next M5, since it will use the exact same engine. To me "bmw M" is dead, the only thing that set them apart from the competition was that the engines were so crazy, almost race-car like crazy, and now, they jump on the "bi-turbo efficiency" band-wagon just like mercedes and audi. At least mercedes does it right, the new 5.5 AMG engine sounds pretty spectacular from what I've heard (altough weak compared with the 6.2)