Host: Is it okay to mix octanes? David Rizzo: It is okay. In fact, that's what gas stations do. When you have got three choices Regular, Midgrade and Premium. Believe it or not when those tanks pull up, the tanker trucks, you see two tanks. One is high octane, one is low. They put them, the high octane goes in the high octane tank, the low octane goes in the low octane underground storage tank and guess what goes in the middle, a 50-50 mix. So, the gas stations mix it, you can too. The better question is why? Why bother? We already know if the car says use 87, use 87. If it says use 91, use 91. There is nothing to be gained by mixing. No, it won't hurt, but why do it?