API’s Engine Oil Licensing and Certification System (EOLCS) is a voluntary licensing and certification program that authorizes engine oil marketers who meet specified requirements to use the API Engine Oil Quality Marks—the API Service Symbol “Donut” and Certification Mark “Starburst.” This program is a cooperative effort between the oil industry and vehicle and engine manufacturers Ford, General Motors, and DaimlerChrysler; the Japan Automobile Manufacturers Association; and the Engine Manufacturers Association. Performance requirements, test methods, and limits are cooperatively established by vehicle and engine manufacturers, technical societies like the Society of Automotive Engineers (SAE) and the American Society for Testing and Materials (ASTM) and industry associations like the American Chemistry Council and API. Oils meeting these requirements are recommended by vehicle manufacturers.