I wasn't suggesting that the engine will fail if he doesn't change his oil, I'm just reinforcing the fact that the price of an oil change is small potatoes and is excellent insurance against future problems. Do the oil change and spend a few minutes under the car while you're there giving everything a quick once-over. You never know what you'll find probing around under the car with a flashlight while the oil drains out. Consider it bonding time with your 911.
