New guy here so you'll have to excuse my basic questions. I'm still picking up bits and pieces here during the countless hours reading & reading... I posted a while back about what type of oil would be good for me and after searching, I've found the MaxLife I have in my car isn't very well liked here while Pennzoil and Castrol GTX are very good dino oils. Both these oils I understand have moly in them, but can anyone tell me any differences between them or explain the "group __ base" thing to me? I'd be using 10w-30 and going no more than 3-4k on the oil. Thanks!