[ORANGE U NV]

Oil has changed drastically in the last 30 years, especially with synthetics. The old method of every 3K is way out dated. V8's back then only held 5 quarts, had case iron blocks/heads and where not built nearly as well as todays engines. There are lots of threads on oil changes and some have had thier used oil tested. GM's has invested a lot of $ in thier oil life monitoring system and all evidence is it work very well. It's not a simple light that comes on every 5K or something, it monitors all your driving and computes the oil's life.