I was picking up some fuel the other day and the guy asked me if a wanted Sunoco, or VP. I asked what the difference was and the guy behind the counter said the racers prefer the Sunoco because it wasn't paraffin based and had lead in it. It also doesn't scale up in the complete fuel system, so he was told. And as a bonus it's a few bucks less. Like 10 bucks less for a 5 gal can. The racers that told him this have been wrenching on pros bikes for years. Anybody here have any input on this?