Best oil for heavy vehicle?

[DieselDweller]

My van with a 6.0 is 11,000 lbs, and I do a lot of mountain driving. I'm wondering what folks think is the best commonly available and reasonably priced oil to run in it?

Thanks-

[mustangman02232]

shell rotella 1540 or syn 540

[Shooter04]

I only trust mororcraft 15w40. Made for powerstrokes

[diesel_dude67]

My uncle recently advised me (service manager at ford) that they switched to 10W30 all year round (all temps) and have had less issues. Along with doing an oil change every 5000 miles and fuel filters every 10,000 they have engines with 250,000+ NEVER disassembled in any way

[clueless10]

I need to replace my 1st injector but don't know where it is located can some one please help.