Oil is used in two ways. Either you have a leak or it is going out the tail pipe. Look carefully at the tail pipe when you first start the car and see what color the smoke is.
A wet and dry compression test will tell you about the engine. If you have bad rings or valve guide seals
What grade of oil are you using and what kind of filter? Let me know
Monday, June 5th, 2006 AT 5:21 PM