It works okay in most applications but you have to watch out for the lead. It will kill O2 sensors over time. It also changes the way you read plugs. I don't think I'd use it in a serious race engine but I know lots of guys who mix it with unleaded to give an old muscle car a little more octane.
X2...this is the way I run it in my GTX, seems to work fine, been running it this way for the last year or so..."seat of the pants" feel tells me it pulls a little harder than straight super unleaded...and the exhaust aroma is an added benefit
