JASOStandards

JASO Standards refer to the set of technical standards published by the Japan Automobile Standards Organization (JASO) that govern automotive lubricants, fluids, and related testing methods. The standards aim to ensure compatibility, reliable performance, and environmental compliance for Japanese-made and globally marketed vehicles and engines. JASO standards cover lubricant classifications, testing protocols, and performance criteria for engine oils, gear oils, automatic transmissions, and other fluids.

A well-known example in the motorcycle sector is the MA/MB classification for motorcycle engine oils used with wet clutches. MA oils are designed to provide higher friction to prevent clutch slip, while MB oils have lower friction properties. In addition to product classifications, JASO issues test methods and evaluation procedures for properties such as viscosity, friction, oxidation stability, evaporation resistance, and emissions compatibility. The standards extend to other automotive fluids and components, reflecting the broad scope of lubricant and fluid performance.

Manufacturers and original equipment manufacturers (OEMs) often specify JASO conformity for products intended for use in Japanese-market vehicles, and many international markets recognize JASO ratings alongside other standard systems such as ISO and API. JASO standards are developed by technical committees that include input from oil companies, equipment manufacturers, testing laboratories, and academia, with processes that may involve public comment and periodic revision. The standards facilitate cross-border trade by providing a common reference for product performance and interchangeability, while accommodating regional regulatory differences. For practitioners, JASO conformity signals a defined level of quality and compatibility when selecting lubricants and related fluids.