Hi all,


First I'd like to say that I've learned a plethora of info here in the last couple months. I was finally able to get rid of my lemon 2003 2500HD 6.0 and step up to an LLY last Saturday! I'm amazed at how quick this thing is. I have a question about engine oil, however!


All the parts guys at the local dealer swear up and down that the Duramax's come from the factory with Mobil 1 Delvac 5W-40 FULL SYNTHETIC OIL! I am planning to use a quality synthetic, but from the research I've done, it seems like the general consensus regarding this issue is to run petroleum oil for the first several thousand miles before switching over to full synthetic.


Is this correct concerning the factory fill? If not, what do these engines actually come with?


What do you guys suggest?


Thanks for your help!

LOL........... OEM is from Chevron.


I break in new motors in with dino oil then, I switch to Delvac 1.





Burner-----------> http://www.dieselplace.com/forum/smileys/Big Smile.gifEdited by: Burner

I'm with Burner, I use dino for break in.


Don't be confused by the Mobil 1, Mobil Delvac 1 thing, they are not the same oil. In fact, IIRC, Mobil 1 does not meet the service spec for your Dmax. I believe the new Mobil Truck and SUV oil does meet the spec and some around here have suggested it's just re-package Delvac 1. There is also a Mobile Delvac 1300 which is dino and it's what is in my truck now. It's 15W-40 and meets the Dmax specs.


What ever you decide to run, just make sure it meets the service spec...http://www.dieselplace.com/forum/smileys/Ermm.gif

I hear good stories about Shell Rotella 15-40. Dino oil but inexpensive enough that you can change out every 5,000 miles or so if you wish to. I'll run it to 15,000 or so then change over to either Rotella 5-40 or Mobil Delvac 1 at that point. These are synthetics. Like the prior posts here, I think dino is best during the break-in and early running period. Be willing to bet that the factory oil is whatever comes down the pike at lowest cost.

I got it from the horses mouth MOBIL..that the truck SUV oil is the same as Delvac1. The specs are the same also on the web site.

anyone run the amsoil diesel specific oil?

anyone run the amsoil diesel specific oil?

I run amsoil and have been happy with it.