Open discussion, thought I'd toss out a few data points as our 930s are very tough on oil....
Friend is a chemical engineer and does not appreciate the Mobil 1
PR machine. Feels that Redline is the best synthetic oil available:
> redline is expensive and you get what you pay for.
>
> if you look at the HTHS specs (high temperature, high shear)
> nothing compares to redline. this is the best indicator of how
> well an oil can stand up to a high revving turbo engine.
>
> if you look at the flash point, the redline is also higher
> than just about everything else.. this is the temperature
> where the oil vaporizes.
>
> mobil 1's numbers are going downhill and people have
> discovered (from the material data safety sheet) that
> they have started to put in cheaper dino based ingredients
> compared to what their original formula was.. this is
> not information that marketeers can spin.. they have to
> say what the oil comprises of.
>
> there was a huge controversy at the oil geek web site
> over mobil 1.. and mobil has been very evasive
> to inquiries.
>
> also, people have sent used mobil 1 for analysis and
> have found that they don't hold up as well either.
> the M1 0W-40 is pretty bad, it degrades after just
> 5000 miles to a 0W-30 and will no longer be
> adequate for a turbo engine.
>
> let me know if you need more info...