Royal Purple is an American manufacturer which produces lubricants for automotive, industrial, marine, and racing use. It is known primarily for its line of synthetic Royal Purple Motor Oil products used in gasoline and diesel engines. It also produces fluids including gear oil, transmission fluid, power steering fluid and industrial gear, bearing, engine, and hydraulic oil. Other products include chassis and bearing grease, lubricant aerosol, aerosol chain lubricant, and firearm lubricant.