I own a new E39 M5 since last april. At 2700 BMW had to add 1 liter of oil, now at 4200 km again they had to add 1,5 liter. BMW Netherlands claims that this usage of oil will remain until 15.000 km, and that after that period oil usage will decrease or even disappear. Does any 'more experienced' M5 driver have anything to mention about this subject?? I am worried.. Also, my gas usage is 1 liter on every 6,5 km. I think that's outrageous. Will it stay that way?