Starbrite Star Tron Enzyme Gas Treatment Unique enzyme formula improves performance of all engines and reduces emissions. Cleans entire fuel delivery system from tank to injectors and combustion chambers, removes carbon deposits, and prevents future deposits. Rejuvenates old fuel. Ideal for all 2 and 4-cycle engines under all conditions. Improves performance when using E10 fuel and also stabilizes fuel for 1 year, making it the all-season, all-purpose additive. Does not contain alcohol. 1 fluid oz. treats 6 gallon of gasoline. (1) 8 oz. bottle treats up to 48 gallon of gasoline.