The Lucas Oil Complete Engine Treatment provides a comprehensive, high-quality solution to clean, lubricate, and improve the overall health and performance of nearly any engine that is gas, diesel, four-stroke, or two-stroke. It is designed to be used in fuel or engine oil. When added to fuel, it cleans and lubricates multiple systems within the vehicle, removing deposits, protecting against corrosion, and ensuring a more complete fuel burn. This correlates to lower emissions as well as increased power and fuel mileage. When added to engine oil, Complete Engine Treatment cleans the engine, while also forming a protective barrier against heat and improving oil flow in cold weather.