VPS Super Concentrated Fuel Injector Cleaner contains synthetic cleaners to remove deposits from intake valves, fuel injectors, ports and carburetors. Power and performance can be reduced if deposits are allowed to accumulate in these vital areas. VPS Super Concentrated Fuel Injector Cleaner removes power robbing deposits to help your engine run as it was designed to run. It smoothes out rough idle, improves acceleration and reduces harmful emissions. Safe for catalytic converters and oxygen sensors. Contains no alcohol. One 10 ounce bottle treats up to 20 gallons of gasoline. Can be used with all gasoline and gasohol. VALVOLINE PROFESSIONAL SERIES FUEL RAIL CLEANER is designed for professional use only. Detergents and cleaner added to the fuel tank may require up to three or four hundred miles of driving to remove troublesome deposits. VALVOLINE PROFESSIONAL SERIES FUEL RAIL CLEANER allows professionals to remove deposits quickly and then diagnose any mechanical failures if fuel related problems persist after cleaning. VALVOLINE PROFESSIONAL SERIES FUEL RAIL CLEANER contains powerful synthetic cleaners to clean fuel injectors immediately and removes deposits from intake valves and combustion chambers. These powerful synthetic cleaners are injected directly into the fuel system without being diluted with gasoline like cleaners added to the fuel tank.