Originally Posted By: used_0il
That graph indicates that I should use a 0W40 in the winter.
Seems like the world is moving on who, TiredTrucker?
The people who build the Duramax, but can't figure out engine oil?
Lets compare an engine with a 35L oil sump that runs up to 1,750 rpm,
to an engine that will run at 4,500 rpm (under braking) with an 11 liter sump.
The crate engine for a GEAC44 is $1.5M, has a 500 gallon sump and runs on 20W40.
What does that have to do with the Duramax? Nothing.
Oh, and another consideration; XW40s protects against fuel dilution better than XW30s.
Hey, you started throwing around the $86K price of your 3500 like it was some sort of badge of distinction. I just mentioned that some of us put a lot more on the line than that and have no problem with 30w oils in some of those applications. If you paid that much for a 3500 Dmax, you got ripped off. Sorry. Didn't want to say it before just to be kind, but you upped the ante so deal with it. And if you didn't pay $86K for the 3500, then why include that amount in your argument? Just to be a little melodramatic? And yes, the world is moving on from your antiquated views on what makes or breaks an oil.