Ok, ignore the question I asked earlier, lol. Right now I run QS Full Synthetic in my 2004 F-150 4.6L. Just wondering, is their a better oil and would i do me any good to switch right now (Truck has 85K). I heard Mobil 1 and Pennzoil are supposed to be better, but I get Quaker State cheaper. Should I spend the extra bucks and get a better one? Thanks