Maxima Hi-Test is a concentrated octane booster legal for all types of competition. Hi-Test is an all organic product containing no metal (lead, manganese or phosphorus) compounds. It readily mixes with all gasolines as well as alcohol and nitro mixtures. Hi-Test will suppress detonation and pre-ignition by modifying the burn rate and increasing the auto-ignition temperature of the air / fuel mixture. The use of Hi-Test in your gasoline will eliminate "pinging" and "knocking" and the potentially destructive results of them. It will allow for higher compression ratios and therefore more horsepower. Hi-Test should be used in concentrations of one to four ounces per gallon of gasoline. One ounce per gallon raises the effective octane number approximately four points, depending on the base gasoline octane. For racing or very high compression engines, or very low quality fuel, higher concentrations of Hi-Test may be required. Raises octane level.