Gentleman,
Again the 2003 manual says nothing about synthetic oils. Why? There are 10W40 0ils that are CI-4 already on the shelves. This all make me wonder how in the know or at least up to date GM is on the oils available. I'll keep reading. Two things I am becoming sold on are oils with protective properties of a 40W (for a diesel). But these newer oils that are thinner and flow more efficiently make sense also. 5W40 would be the ticket if it wasn't OD on polymers.
Could we set up a poll on oils that are being used?(administrator)? It would be interesting I think, now that college football is over.
What a subject! The life blood of our toys. I have learned alot but not sure of anything...yet.
Thanks again to all.
Steve
2003 Silverado 2500 4x4 Duramax loaded Crewcab w/Allison, Shortbox line-x,prodigy,equalizer hitch,husky floor mats and flaps, Amsoil Air in ,Banks Monster out