Oil is oil these days if you keep up on maintenance. There is no one oil that is superior to another when comparing conventional to conventional and Synthetic-Synthetic.
Mobil 1, Valvoline, Castrol, whatever is on sale in synthetic is what goes in my ride. 5w-20 for MDS engine's. The diff fluid is Synthetic from the factory so only use Synthetic when you replace the diff fluids. 75w-90 front 75w-140 rear as stated for 1500's. But then again, the owners Manual will tell you the same info.