Originally Posted by gatoman39
No, I didn't. I will at the next one which will be 10k miles. This guy with an N55 motor did, it's the first N55 UOA i've ever seen:
Interesting report. As far as viscosity, this oil has sheared a fair amount. If I'm not mistaken BMW's 5w-30
SUS viscosity 210F starts at 12.2 and its CST @ 100C starts @ 66. In other words, the BMW synth starts out as a heavyweight 30wt, but this sample shows significant thinning. Still in grade, but on the thin end of the spectrum. Thinning is often a result of fuel dilution, which these BMW turbo engines are known for (also noticeable in the black deposits on my 535's exhaust tips). Another indicator of fuel dilution is the manganese number (a gasoline additive) of 5, which is fairly high for a sub 2k mile run.
This is why I don't anticipate running my oil out to the recommendation of the oil life monitor. I'll probably sampe at 5k miles on my second oil change interval (changed originally at 1200 miles) for a total of 6k miles on the car mostly to see who the viscosity is holding up and where the fuel dilution markers like Manganese sit.
We'll see how my green GC holds up in this fuel diluter.
Gatoman, are you active on the BITOG site?