Question for BigMIke: What data/experience do you have with AMSoil to prove that it is the best? I don't disagree that it might be the best, but I am just curious why you feel so strongly about it.
For All: Anybody run Synthetic Blends? When I put Castrol Syntec in my Tundra I noticed that the engine seems to run a little be smoother and quieter. I was worried about the leak issues with my wifes Cavalier so I opted for Castrol Blend and it had a similar effect on the engine. I am not sure if all Blends are essentially the same or if they are all completely different. Syntec claims a conventional base oil, while Valvoline claims a synthetic base. Anyone know anything about this? How about AMSoil Blend?