Interesting site. Wonder if that temp is specific to the Duetz engines as they are air cooled? Those Duetz engines are pretty cool, (pun intended). Does it make a difference if it is Synthetic or Dino oil? The synthetic oil would help the engine run cooler.
That would be more like a temperature I would expect (275 F). Also where are they measuring the oil temperature? I would expect the max temp for an oil would be specific to that oil, and how long it could sustain that temperature. I am measuring it before it goes into the cooler, as I figure that is worst case, aside from measuring right at the piston. I should install another temp sensor after the cooler.
1993 K3500 - Peninsular 18:1 engine, marine injectors, high capacity cooling, AL Core Radiator, 3" DP and 4" exhaust, ISSPRO Gauges, Girdle, AMSOIL Dual Oil Filter System, 1997 Air Filter(trashed the K&N), 395K on Body, 165k on engine.
1997 GMC Savana - 6.5 TD
1966 CJ5 - V6 Gas - highly modified
1967 Jeepster - Stock
1986 Jeep CJ7 - Stock
1993 Grand Cherokee - 6.2 diesel
2007 Grand Cherokee - 3.0 diesel