umm ok this is the 2nd time i have to change my oil since i got my truck and before i just took it to the dealer cuz i had a free lifeitme oil change deal but then i got pissed at the dealer becuase of other things and anyway got it refunded

so i am wondering what i should use for a high performance oil since many people here seem to be saying that some oils are better than others?

im looking at royal purple or amsoil but i dont know where to get either of them or if i have to change my own oil or bring it to a shop somewhere?

 

I like the Shell Rotella T Synthetic 5W-40 or Mobil-1.