Originally Posted By: bigsteve
I just downloaded the manual online and it said to use GM6094M. I did not see anthing about using synthetic oil is there a message that was sent out or something else?
No, this was a midproduction running change. No TSB's issued.
You would be better running the synthetic oil as there was no changes to the engine in your truck to the 08+ but the factory recommends it now. It was done ,mainly to reduce noise. But you will in no way damage your engine if you continue to use a good dino oil, of course.