http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_Turbo_Diesel_Truck_5W-40.asp I would have to go with M1 TDT 5w40. I was looking at OVERK1LL's UOA and then looked at the PDS for M1 TDT. All things considered (performance & availability), M1 TDT is the best oil out there IMO. I would not hesitate to use this oil in a high performance gas engine either. I know it's holding up very well in many of the VW engines too. All things considered, I'm not sure this oil can be beat. Rotella 5w40 & SSO would be up there also.