That paper seems to be about the turbochargers used on the first series of G3600 engines in the '90s. Given that turbochargers are a scheduled changeout item (25,000 hours IIRC), I would think moving to the newer part number would be a straightforward decision. I am a little removed from that area now. I was involved in the first ever customer installation of a G3616, a 3 mW genset we installed at a power station in the Canadian Rockies in 1991. It was pretty reliable, and I suspect it is still running (it would be well over 100,000 hours now). EDIT: I went and looked up the paper. It took me back, and I remember the part numbers, the Asea Brown Boveri (ABB) VTC254 turbos. They were huge.

I agree that diesel has lubricating qualities, more so on #2 fuel oil than other grades. A significant issue we used to have with winter fuel that was blended with #1 and #2 was the reduction in lubricating qualitities (the designers called it lubricity) and resultant failures, particularly the hydraulic unit injectors. The pre-cup diesels that used to lubricate the cylinder walls are long gone now, due to emissions rules. With modern direct injection systems, whether diesel or gasoline, I don't see much impact of the fuel washing down cylinder walls. I could be wrong.

I think if we are comparing compression ignition engines to spark ignition engines (gasoline, CNG, propane, etc) then other variables should be equal. That would suggest that we should compare turbocharged engines to turbocharged engines, and NA engines to NA engines, whichever cycle the engine is operating on. With BMW's move to turbos on new models, it is likely a moot point, as NA engines will become less common.

Interesting discussion. Always up for an engine thread, it makes a nice change from the threads about which 22" all season tire to buy or what % tint, lol.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue