typical manufacturer oil change timeframe is ~5K miles. The oil life monitor on my truck triggers about every 5K although that manual says it is based on run time, rpm, miles and calculated load.

As much as I hate them, Consumer Reports did a review on Oil Life and stated that you can go 5k without a problem, depending upon driving habits. I believe they did a study with taxi cabs in NYC.

http://www.xs11.com/stories/croil96.htm

I know this doesn't directly relate to this post, but that could very well be why GM setup this engine oil life system the way they did.

(I still change my oil every 3k!)

I change my oil at 3K as well. Personally...I know that CorvetteCrazy and myself both saw cleaner engines after 1 year. Sludge etc cleans up nicely with regular 3K changes. In the end..you have a clean motor w/o sludge or any buildup from running the oil longer.

The way I see it, oil is cheap and if you want you engine to last, then change it more often then every 5000 miles.