Greetings all! I'm a E24 guy with a question about a friend's E46.

What actually triggers the Oil Service Indicator? Friend's car had an oil change about a year ago, just before she headed to Iraq. Her mom just took the car into the dealer for a state inspection, and they told her it needed another oil service.

Her mom drives her car about 1 day/week, so it probably has <200 miles since the last dealer service. Does time (as well as mileage) trigger oil service intervals, or does something else trigger it?

One additional question: she's worried about what oil to use. Do E-46s require BMW oil, or will Mobile 1 (or AMSOIL/Redline/Royal Purple) be sufficient?

85 M635CSi
86 657CSi
08 XRunner