X6 is so big that it gives you the sensation that acceleration is not that great (if you just watch the traffic). I still wonder why all other cars (almost one ton lighter) are taking off so slowly, and remain behind at 200-300 meters
If you watch the tacho you'll notice that at 60 kmh you are only at 1500 RPM. . At 120 kph, you are at 2200 RPM or so. The first few meters from take off at green light are slow, then you catch up speed much faster. But even for cars with manual trans. 1st gear sucks.
PS: To take off with the X6, you need a bit more thump than with lighter cars. So bigger torque is needed. Once you get the high torque, you can built speed with less effort on gas pedal. So higher torque right from start helps the X6. I have now about 850 km with the tank and it responds faster to acceleration. The engine starts to learn faster power building