Definition
JASO (Japan Automobile Standards Organization) develops lubricant specifications for motorcycles and other Japanese automotive applications where global standards do not fully address local requirements.
Key JASO 4-stroke motorcycle oil standards:
- JASO MA — standard friction; for wet clutch motorcycles requiring assertive clutch feel
- JASO MA1 — lower end of MA range; specific dynamic friction index requirements
- JASO MA2 — highest friction; for most sport and standard motorcycles with wet clutches
- JASO MB — lower friction; for scooters and mopeds where clutch slippage is not a concern; NOT suitable for wet-clutch bikes
JASO 2-stroke oil:
- JASO FC / FD — cleanliness grades for air-cooled and water-cooled 2-stroke engines