[WardL]

You might consider NASCAR engines are completely rebuilt after each race. NASCAR has much different needs than any street car. Some of the additives in fuels are designed to keep deposits out of the engines. I have to disagree with G-Pete in that the refinery does not add water to fuels. There will be traces of water in all fuel due to processing, but when the fuel leaves the refinery it should be "dry". Perhaps we are missuderstanding each other by the definition of the refinery and the truck loading terminal. Ethanol is almost always added to gasoline at the terminal where the tanker trucks are loaded for delivery to the retail site. Many refineries have truck loading terminals, but there are many terminals not close to a refinery. The blending of ethanol into gasoline adds a lot more dissolved water in gasoline.

The driver and car (tires, power, etc) have more to do with sucess on the weekend track than switching from retail premium fuel to super duper racing fuel. This is particularly so in an over-powered Cobra. I'll take my $4/gallon premium anytime over $8/gallon racing fuel.