Gateway Riders BMW Club Technical Director Presentation
by Ted Schmitz
Motorcycle Oil Standards
Introduction: I am going to talk briefly about motorcycle oil standards. Since the API (American Petroleum Institute) does not currently have standards for motorcycle oil, I will talk about the JASO (Japanese Automotive Standards Organization) standards.
They are as follows:
JASO T903 MA – these are oils for 4-stroke motorcycle engines with a single lubrication system for the engine, clutch and transmission, i.e. those with a wet clutch that is lubricated by the oil, and the transmission incorporated in the crankcases. These oils contain no friction modifiers and deliver the needed friction performance to prevent the clutch from slipping.
JASO T903 MB – these are oils for 4-stroke motorcycle engines with an automatic belt transmission
(known as a constantly variable transmission or CVT) as used on most scooters. These oils contain
friction modifiers to reduce the amount of friction in a running engine and so deliver improved fuel
economy.
JASO T903 F – these are oils for 2-stroke motorcycle engines.
Additional JASO T903 MA standards
MA – as mentioned above, is a standard specification for engines with a single lubrication system for
the engine, clutch and transmission.
MA1 – lower standard specification for engines with a separate lubrication system for the gearbox.
MA2 – higher specification for engines with a single lubrication system for the engine, clutch and
transmission and with a catalytic converter in the exhaust system.
In conclusion, you should chose your motorcycle oil following the manufacturing specifications having the highest JASO standards appropriate to your motorcycle.