Today I called BMW Silver Spring to schedule oil service on my E92 M3. I noticed on their site that they had an oil service coupon for 8 cylinder cars that covers up to 10Qts of oil. I know these coupons don't apply to M cars but I figured since the lady who answered the call was being so helpful that I would ask, what is the difference between changing oil on an M car with 8 cylinders versus a non M car with 8 cylinders. She politely asked if she could put me on hold to get that information. When she returns she informs me that M cars take more oil and that is why it costs more. To my knowledge my e92 M3 takes 9 Qts. Can anyone explain to me what the difference is between changing oil in an M car is versus a non M car?