Prior to the current fuel price craziness, I was buying E-30 fuel for about $1.30 less than regular fuel. An octane booster adds about 20 cents per gallon to the cost of fuel. Is an octane booster a cheap way to counter the lesser MPG that you get with ethanol fuels? I don’t notice much difference in MPG between E-30 and regular fuel. I notice that the octane booster bottle doesn’t give much information about how much they are supposed to help boost octane.