Check out the info onstar has...

[marin8703]

Got my monthly diagnostic report and got to a page where the onstar history is shown. the two things it has is oil life history and average daily driving, might have more but couldnt look around. Im liking this onstar thing, its evolving, hopefully soon it will have many more usefull features. This is pretty cool!!! Heres a couple of screenshot:





I gotta start changing the oil less frequently.

Another good thing to track would be fuel economy, but it doesnt.