What oil do you use?

[FATCAT]

By the way, on that same forum, you said something about needing to continue to use synthetic oil after you start using it. I have never heard this and am skeptical. Where did you hear it?



Loren

That statement I remember hearing from a service department manager. He said that if the truck comes from the factory with synthetic oil, you must ALWAYS use synthetic oil. So apparently this guy did not know what Cummins puts in their engines from the factory -or- he is just trying to sell the Mopar synthetic oil at $7/qt.



Now that I know that the engine come with Valvoline Premium Blue (non-synthetic), I will stick with that and save some money. Maybe in time I'll switch over to AMSOIL Syn 5w-40 DEO oil (since I put AMSOIL in everything I have), but until then I'll just use the Valvoline.



Thanks for the info.