[tirebird]

I've been using it for some time now. Before rebuilding the LS6 I used it in any tank of lousy California ethanol diluted 91 octane. I wouldn't use it when I filled up with 100 unleaded or 110 leaded at the local track. Now that I've rebuilt the LS6 with 9.5 c.r. heads/pistons, I don't use it that much. However, when I do throw a bottle in, even with the lower compression, my SOP feeling is the car is more responsive and powerful. But that's not science, just my impression.