dcstep wrote Jamie, of course, a mechanic will always recommend excessive oil changes. Why don't you tell the class your markup on the synthetic oil used by the M3?
I prefer to take the advice of the car manufacturer, who's on the hook for the warranty.
Dave
My friend, the BMW warranty only goes to 50k, 100k with the extended warranty. You have to realize that the engine will be fine up to 100k at their recommended interval. It will be later on down the road that issues will crop up due to excessive wear from sludge build up and blocked oil passages causing oil starvation to various parts of the engine. You also have to realize that BMW only changed to the longer intervals when they started including free maintenance, a coincedence, I think not. Like I said in a previous post: If you intend to keep the car for a long time or >100k change at 5K. If you are only going to have it for a few years or <100k follow their schedule.
P.S. the only reason a mechanic would recommend excessive oil changes is that oil is cheap compared to repairs. Oh and mechanics dont get any kickback from oilchanges they are paid flat rate to do them. I am a Heavy Equipment Technician, I don't work for a BMW dealer so it makes no difference to me.