hi all,

I have a question regarding engine oil in my car. Actually it has been happening to my car regularly. For every five thousand miles driven, my FSS will show add one quart of oil ,and then another one hundred or two miles driven FSS will show add 1.5 quart. I used the oil dip stick to check the oil level and it shows bare minimum. It's has been happening since I bought the car new, and had gone back to dealership numerous times for oil leakage and found no oil leakage. My car is a 1998 E320 and has swithced to sythetic oil at about 12000 miles. Can anyone point out what's wrong with it? Is anything wrong with the engine? Where did all the oil go? Thanks for all your inputs.