What does JASO MA Mean?



Victory & Indian motorcycles use the same oil to lubricate the engine and clutch. The oil must exhibit the correct frictional properties or else the clutch can slip. Since passenger car/light-truck oils often contain friction modifiers to improve fuel economy, they aren’t recommended for wet-clutch applications. Instead, you need to use an oil with the JASO MA rating.

The JASO classifications can get a little confusing; let’s break it all down.

What is the JASO standard?

The Society of Automotive Engineers of Japan (JSAE) developed the JASO T 904 standard to classify oils by their ability to provide good wet-clutch lubrication and performance, helping enthusiasts select the right oil for their motorcycles.

The JASO specifications are the Japanese equivalent to the American API standard and were introduced partly because the API standards used for oils weren’t up to the job for modern engines.

What does the JASO standard measure?

It measures an oil’s frictional performance in the SAE #2 Clutch Friction Test. Specifically, the oil is tested in three areas:

  • Dynamic friction: Best thought of as clutch feel as you let out the clutch lever and transfer power from the engine to the transmission. This is especially important for heavier bikes or bikes that carry a lot of rider weight. If the clutch slips too much, the bike loses momentum and can wear out the clutch discs. If the clutch grabs too much, the bike can stall.
  • Static friction: Think of this as the clutch’s holding power once the clutch lever if fully released and engine power is flowing through the transmission. Oil’s with poor frictional properties can allow the clutch to slip under high-torque conditions, like a powerful cruiser riding up a steady incline.
  • Stop time: A measurement of how quickly the clutch engage.

Point’s to consider when selecting a JASO approved oil…..

1) You get what you pay for! When buying oil you get what you pay for. The correct oil for your Victory or Indian motorcycle does not cost $5.99 /qt at Walmart! Do guys use it and brag? Yes. Do you think they come back and say my clutch is slipping-- Uhh, you know the answer..

2) Cheap automotive 10w40 oils aren’t suitable for all bikes! If you’ve got a Victory or Indian motorcycle, you need to bite the bullet and buy the correct oil for it (when you see up close the very fine tolerances modern engines work to you begin to understand why, sometimes the cheapest oils just aren’t worth the risk!)

Where to find the JASO information on an oil bottle…..

Normally the JASO and other oil specification information will be printed on the back label.