Man, you guys are all over it. If you want a good laugh, go to e46fanatics where every other post is pratically, "why does my need oil light keep coming on?", or "if BMW says change every 15,000 miles it must be best for the engine."

I change according to the service indicators with Mobil 1 0w-40 (A good Group IV synth v. Castrol's Group III crap). Normally, I agree with 7500 miles as a reasonable limit, but for a few reasons feel confortable pushing it out to 8500 or whenever the lights come on. BMW's (and most german cars) have large oil sumps compared to domestic and Japanese cars, which allows for longer intervals. Second, synthetics maintain their additive package longer than mineral oils and are suited for longer change intervals.

As another poster said, check out bobistheoilguy.com There is a wealth of information, including Used Oil Analysis.

Cary