Free: Contests & Raffles.
I run delvac 1300 in mine. It's also excellent oil. I wouldn't run synthetic in a duramax myself. Not worth it.
Unless you're going to run extended oil change intervals,or live in the arctic don't waste your money on synthetic. The Duramax has proven to be very easy on oil. Run an appropriate conventional oil, follow the OLM and the engine will last longer than you'll probably want to drive it.
Not entirely sure if there's any logic in this, but I've always been told to wait until there's 10k miles on the engine before switching to synthetic.
Quote from: jackelope on October 15, 2016, 12:01:15 PMNot entirely sure if there's any logic in this, but I've always been told to wait until there's 10k miles on the engine before switching to synthetic.The theory behind it was Synthetic oil didn't allow all the parts and pieces to get "broken in" properly. Race engine builders will run a new motor on their dyno and use special "break in" oil to achieve the same thing.I'm a big fan of Royal Purple and that's all I use in my gas motors but when I still had a diesel I used nothing but Valvoline Premium Blue. If I had a diesel pickup now, Premium Blue is what it would get.
Anybody use Mobil 1 in their diesel rig? I bought a Dura Max a couple months ago and it's time for an oil change. I noticed on the Mobil 1 container that it's for gasoline engines and it doesn't have the letter designation for diesel engines. Any help is appreciated, thanks.