I can't get the 5w40 in my area, at my local Costco I can buy either Mobil1 5w30 or 10w30. Which one one is my best bet at this time of year in southen California? Thanks in advance.

Mobil 1 is not diesel rated oil. You have to look for a CH (or CI or CJ) API rating. That means you should be looking for Mobil Delvac 1 or Mobile Truck and Turbo. A good economical alternative is Shell Rotella-T synthetic in 5W40, Rotella-T non-synthetic in 15W40 or even Mobil Delvac Super 1300 in non-synthetic 15W40.

Mobil 1 is not diesel rated oil. You have to look for a CH (or CI or CJ) API rating. That means you should be looking for Mobil Delvac 1 or Mobile Truck and Turbo. A good economical alternative is Shell Rotella-T synthetic in 5W40, Rotella-T non-synthetic in 15W40 or even Mobil Delvac Super 1300 in non-synthetic 15W40.

It does say for Turbo Diesel.

The manual says to use 15w40.

I run the Rotella T 5w30 syn. No problems and oil analysis comes back pretty good..

My dad is now converting over to the same oil as I.. He used to run the rotella T 15w40 dino.. We've always stuck with Rotella ... Seems to keep our truck running :D ;)

i have 95,200miles on my truck and he has 137,000miles on his.. NO major probs at all with either.


-Colin

Thanks to everyone for their replies. I'm leaning towards the 5w30 Synthetic. I double check the box it only says (Mobil1) fully synthetic oil. Can anyone explain the full process of oil analisys?