The European Automobile Manufacturers Association (ACEA), founded in 1991, represents the interests of the sixteen European car, truck and bus.
ACEA maintains close relationships with all the national automobile manufacturers' associations and with a number of organisations, having interests related to the automobile industry. These include the European Association of Automotive Suppliers (CLEPA), Intelligent Transport Systems - Europe (ERTICO), the European Committee for Motor Trades and Repairs (CECRA), the European Road Safety Federation (ERSF), the Fédération Internationale de l'Automobile (FIA) and the Union of Industrial Employers' Confederation of Europe (UNICE).

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.

In 1975, the International Standards Organization (ISO), in unison with American Society for Testing and Materials (ASTM), Society for Tribologists and Lubrication Engineers (STLE), British Standards Institute (BSI), and Deutsches Institute for Normung (DIN) settled upon an approach to minimize the confusion. It is known as the International Standards Organization Viscosity Grade, ISO VG for short.