I searched honest!!

[Stlheadake]

I have tried searching honestly! I know this question probably gets asked at least once per month. I also know it has a lot to do with opinion too. What kind of oil are people running in their trucks? Below is what I am ABOUT to do for my 2thousand mile change. The question marks indicate where I don't know what to put in it. What are others running?

Engine: Mobil 1 15/50 or 5/40 turbo diesel synthetic CI-4?
Tranny: ?? What synthetic ??
Rear: Lucas 75-90synthetic? The book calls for 85-90 but I can't find that in Mobil or other in my area
Front: same as above
Transfer: ?? What synthetic ??

I know that there will be opinions, I want to change it out, then likely will give Amsoil a try in the engine at next interval.

So what do you think? Is Mobil good? Rotella synthetic? What about Lucas?

[More Power]

To remove any warranty denial possiblity, I'd stick with your owner's manual & diesel supplement's recommendations for all fluids. This includes API certifications, types and viscosities (engine oil should have API certification CG-4, CH-4 or CI-4).

My 2001 owner's manual & diesel supplement indicate 75W-90 synthetic axle lube for the rear diff.

For synthetic ATF, as long as it carries the same API cert of the dino Dextron III (or IV), you'll be OK. Clint Cannon of ATS Diesel recommended Dextron III (dino) to me last summer for their performance Allison transmissions. He mentioned the friction material used in their clutch packs were engineered for the lube qualities of dino.

I don't necessarily have a synthetic brand choice. When switching to synthetic, I would factor availability into a choice. Choose a brand that you have good access to in your local area and while on the road (unless you buy in quantity ahead of time, and carry some amount with you while traveling).

Jim

[Melvin P. Thorpe]

I use Chevron Delo in the engine and Kendall when I have to go to a local shop.