I've gone by the BMW service schedule for my CPO 2005 BMW Z4 2.5i. All service has been done at BMW dealers including the last Inspection II that was done out of the 50,000 mile free service, which was done at 60,000 mikes. At about 55k miles, my oil light came on, and I added about 1/2 quart of oil. Oil change at 60k miles. At 66-67k miles, I added another 1/2 quart of oil when my oil light came on again. I'm just under 70k miles and my oil light came on two nights ago when I parked my car in the garage, but it hasn't come on since. I assume that i'm probaly going to add another 1/2 quart when I stop at the auto store tonight to buy some mobil 1 sythetic. Before 55k miles i didn't add any oil, what would be the case of this change? Do I need to be worried about this? Also, would this be covered under the 100k mile CPO warranty? BTW, In case this might be pertinant, I got my car with ~13k miles on it when I was living in MD and drove about 50+ miles to work for a few months, moved to boston for 8 months where I had a 25 mile commute to work, then moved to Chicago where I had another 25 mile commute for 14 months followed by a 50 mile commute for 3 months, and now I'm back in md for the past year and a half where I have a 6 mile commute to work. my trip home is often split between 3 miles to the gym, and then 3 miles home. In my last move to baltimore, I came here with about 50k miles on my car. I don't know if it is quincidence, but it seems that I've started adding oil as my commute to work has dropped significantly.