So the manual says trust the computer. The computer says 89% used, 11% to go. It is what it is. My Expy asks for a change between 8 an 10 thousand dependign on how I drive. The Civic asks at around 8500-9000, mind you that is 3.9 quarts at a time, with filter changes.
The 3000 mile oil change came from the oil companies. Guess what, the more often you change, the more money they make. The computer factors in Engine Temp, RPM, Throttle, Load, and Durration, and lets you know when the engine needs new oil. if it says you are okay, you are okay.