Originally Posted by MickeyM3
m6pwr; since you're so generous with your information why do M cars (including the N54 1M's) require fluid change at 1200 and BMW bikes at 600 miles? This seems contrary to your position.
Maybe not. The N54/N55 etc is not an S54, S65, etc. Is It? Do you think the BMW engineers missed that? I asked Hillary about this sometime ago and his response was that on some models the mfr wants the factory fills to be changed early - - the factory fill is designed so to speak to be dumped early (the factory fill on the M cars may be quite different from the service fill). Why on the M cars, I don't know. They are as close to a perfectly blueprinted engine as you're going to get and from real world UOA's I've seen on the 1200 mi oil change, they shed almost zero wear metals at all (as they do for most of their useful life from what I've seen, regardless of whether the ocis' are 5k, 7.5k, 10k, whatever the computer dictates, and the UOA's at 100k look like the ones done at 1200 mi). So from a purely wear metals standpoint I can't imagine why BMW wants the oil to be dumped so early. On the other hand, I don't think I've ever seen a UOA on an M engine where the owner disregarded the owner's manual and ran the FF out to 10k or whatever. What then? Disaster?
It's a mistake to assume that the factory fill on any particular BMW model is the same as the service fill. I know that the factory fill on BMW's family of diesels is not. The same for VW and Audi diesels. They all have a FF of FUCHS lubricant (the so-called factory fill specialist in Europe) that may or may not be significantly different from the Castrol service fill. I know from monitoring the VW TDI board that one person who visited the VW diesel engine factory in Germany was told emphatically NOT to change the FF early. Hmmm. Wonder why?
Don't know if this answers your question. Me - - in God and BMW I trust. If I have an M car and they say dump the FF at 1200 mi that's what I'd do. If I have a f30 N55 and they say take it to the CBS mileage. That's what I do.