My wife drives a '99 Malibu with the 4 Cylinder 2.4 Twin Cam (Quad-4 Derived) engine. It has 50k on the odometer and has had 3K OCIs with conventional oil. It's used in-town almost exclusively, and it does seem hard on the oil, turning it black within a few hundred miles. I have noticed that lately it is starting to use oil . . . maybe a quart every 1000 miles. Anybody out there have any experience with this engine? I know that it isn't one of GM's best efforts, but I figured as lightly as it's used the engine would outlast the car anyway. The car has had no other issues in the 7 years we've owned it. I plan to just keep topping it off and run it. It will be 15 years old by the time it hits 100K and be a rustbucket by then anyway. Any help or other's experiences would be appreciated.