I see gm caved to the epa, they're recommending absurdly thin oil in these 3.0's: 0w/20. Yep, you'll see slightly better fuel economy, but it will come at a cost.
That is fking insane. I don't know what yall's warranties stipulate, but I would never run oil that thin in any diesel. As those bearings and rings begin loosening up, that's not much protection. I bet oil consumption will be prevalent after the first 100k miles.
When these get a few year on em and start showing up used, I'd only consider 5w40 even in the coldest temps.
I wondered the same thing myself Mainer. I have a 2017 Colorado ZR2 with their 2.8L diesel. Just about to turn 160K miles on it and I use the 5/30 Synthetic in it. No oil consumption problems, but I have wondered if I could use 5/40 in it, as it would keep all my oil the same since I use it in my Dodge Cummins and my tractor. Might be too chicken to change at this point as I can't see any issues with the current oil.
Anybody swapped their little motor's to 5/40?
