Originally Posted by strych9
My Porsche called for 15k oil changes...using good old Mobil One.
I've gone to seminars about motor oil, synthetics, etc. A C5 member (Gunny, I think) did testing and proved that there was no significant degradation or contamination in the oil after 8k miles of use.
Synthetic oil will go the distance with no problem. No OEM is going to make that claim unless it's a fact. They are responsible for the warranty, after all.
All bets are off if you're racing it.
The GM engineers changed the oil monitor from 10,000 miles max - to 5,000 miles max interval for a reason.
I expect them to know more about what is going on than any of us, as they do an analysis of field failures.
My guess is there is an oil sludge problem that causes some of the issues.
Maybe a cold spot in the motor? Who knows.
Cheap insurance to go to the shorter interval.