I have a 01 trans am with an ls1 engine. The car is not a daily driver and only have about 5k miles on it. I am currently running castrol gtx 10w-30. I have debated back and forth about going to a synthetic. I was thinking amsoil, but it seems like more hype from their "dealers" than anything. I am leaning towards redline right now. The only thing that concerns me is I read something about it causing build up or oxidation in the engine. Is there any truth to this? Maybe a result of using the racing oil rather than the regular synthetic? Any other opions on redline would be helpful. tia.