Generally, they're all useless, you'd be very lucky to get +1 bhp from some of the well know brands. Toluene is what you want, search the web for more info, check out this article in the meantime.
I use millers actane booost and I seem to get better economey, Im very interested in toluene seems almost to good to be true has anyone tried it i'd like to see the results if any through using it in an FTO.