Old-Raptor-guy
FRF Addict
I would Highly recommend the 5w-40 version ( until I owned a lube/repair shop T-6 is what I ran in everything, diesel oil used to have more zinc which is a HUGE anti-wear additive so yes I run/ran diesel oil in my gas engines, the .gov(EPA) claims extra zinc may or may not cause catalytic converter damage, i'll take my chances, cats $1500, eco boost engine $15,000.)I run T6 15w-40 in my 1996 7.3
@Nex if you live in any kind of climate that sees 50 degrees or lower you will notice much better start ability and drivability with the 5w-40, "cold" performance of the oil is much improved while high temp performace is not sacrificed. the way the 7.3 injection system works "flow-ability" or "viscosity" makes a huge difference on performance.
The oil I run now is "diesel" rated but in the last 5-7 years zinc levels have dropped quite a bit.
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