Royal Purple Max-Clean is a state-of-the-art high performance fuel system cleaner that maximizes the performance of your fuel system. Max-Clean restores fuel economy by deeply penetrating deposits and cleaning injectors, carburetors, intake valves and combustion chambers. Royal Purple Max-Clean is EPA / CARB Compliant.Recommended for use in gasoline and diesel engines and can be used with all ethanol blends or biofuel. Max-Clean can be used in both 4-cycle & 2-cycle engines and will not harm vehicle emissions equipment. RECOMMENDED TREAT RATE Pour entire contents of bottle into nearly empty tank immediately before refueling, then install fuel on top of additive. One (1) can treats up to 20 gallons. For tank sizes outside of this range, use one (1) ounce per gallon. In two-cycle engines, use one (1) ounce per gallon. RECOMMENDED USAGE Max-Clean should be used every 10,000 miles or annually, whichever comes first.