Just got a new 06 550 6 speed(traded an E39 M5). I find that if you are traveling at a steady speed (no matter what speed or rpm) if you lift off the throttle there is a perceptible lurch which seems most noticible if you are in a situation where you are trying to modulate the speed without using the brakes and are backing off and pressing the accelerator by small degrees. I note that it corresponds to when the mpg meter arrow drops into the extreme left area (I presume cutting out the injectors?). It's as if the electronic throttle kicks in too abruptly. I have never experienced this with my other BMWs. I have not addressed this with the service department as I expect it is normal for this car -- but damned disconcerting.

Any comments or explanations?