Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. If you guys drive old vehicles with some real power under the hood you'll see the difference between 87 octane and 93 octane. Try adding 110 racing fuel to the mix. Also Real comparisons cannot be made from tank to tank. Your fuel tank holds a few gallons that dont get used. Adding 93 to a tank that had 87 in it doenst give you 93. Gives you a mix of 87 and 93. I also think more goodies go into 93.