Ok, it is time to bring my trans am out of storage for the winter. Currently all i have run in it is castrol gtx. I thought about royal purple, but was skeptical about it and after seeing Patman's oil analysis, I don't think I want that in my LS1. So would you stick with the castrol gtx or make the change to mobil 1. I still think that the mobil 1 is a little on the thin side, especially for the LS1, although 90% of people I talk to with either LS1 fbody's or corvette's run it? One more thing, I would not even be considering the mobil 1, but at a couple stores around here it is priced at $3.30 a qt. The car is a weekend driver so I don't put that many miles on it and end up changing it more often than need be which is why synthetic might be waste for me, but $3.30 a qt. for mobil 1 is . Thoughts, Opinions, Suggestions?