For 4-Stroke applications, JASO introduced the T903 specification in 1998 as a global standard. The specification was designed to address clutch slippage problems in the field, provide the correct balance between hardware durability and catalyst protection and to improve fuel economy performance in scooter applications. This was in direct response to industry concerns relating to the incorrect use of lower viscosity and highly friction modified lubricants in wet-clutch motorcycle applications and a need to upgrade the quality of four-cycle motorcycle lubricants available in the market.

For 2-Stroke applications, JASO introduced the M345 specification in 1994 as a global standard. The specification was designed to set a minimum level of engine protection and exhaust emissions control performance, in response to industry concerns about the durability of two-cycle engines and quality of two-cycle lubricants available in the market.

Japanese Automobile Standards Organization (JASO)