Some of the guys have went to walmart oil, saying that they're going to change after every race so it doesnt' get a chance to break down. I have a hard time making myself put walmart oil in a $10,000.00 engine. I have always ran Valvoline racing oil, I don't know why I guess it seemed to work for me. But since I've went to alcohol it seems to milk real fast. My vacuum pump is working well so I was looking for an oil that wouldn't mix with alcohol so easily, maybe giving my vacuum a chance to pull alittle more alcohol out.