Some use Grocery store brand no name oil, some synthetic some use their own formulated elixirs. I think using synthetic is the way to go when you consider lubricating properties and stability. I think it really depends on your wallet and preference.
I use 15w40 Shell Rotella T because Rotella t 15w40 has:
Zinc: 0.151% mass
Phosporous: 0.141% mass
The Rotella T meets the latest API specification CI-4 which meets gasoline specs apparently. The zinc content is very high and that gives you more protection than many other standard gasoline dino motor oils.
I may try synthetic next year since synthetic is by far more stable than \"DINO\" oils. But for now I choose Rotella due to its excellent anti-wear zddp additives.
Some use oil of their choice and add 1/2 bottle of GM EOS. The unkown properties in GM EOS gives excellent anti-wear additives. I wonder if it has alot of MOLY which plugs oil filters. Whatever you use as long as you have good oil pressure you should be fine.
