OverviewJASO MA oils deliver higher level clutch frictional performance. They are formulated for use in four-stroke motorcycles and scooters and are primarily suitable for wet-clutch applications. Oils which meet JASO MA performance requirements, can also be sub-categorised into meeting MA2 (higher clutch friction) or MA1 (lower clutch friction) performance. The main physical, chemical and clutch frictional requirements, according to the current version of the standard (JASO T903:2016), for JASO MA oils are shown below: Physical and Chemical
|Sulphated Ash||D874/JIS K 2272||% mass||1.2 max.|
|Phosphorus||D4951/JPI-5S-38||% mass||≥0.08 and ≤0.12|
|Sequence I||D892/JIS K 2518||mL||10/0 max.|
|Sequence II||mL||50/0 max.|
|Sequence III||mL||10/0 max.|
|Evaporation Loss (NOACK)||D5800/JPI-5S-41||% mass||20 max.|
|Shear Stability (Kinematic viscosity (100°C) after test)||ASTM D62781)||mm2||xW-30 : 9.0 min. xW-40 : 12.0 min. xW-50 : 15.0 min. Others : Stay in grade|
|High Temperature High Shear (HTHS) viscosity||D4683/JPI-5S-36||mPas||2.9 min.|
Note 1) : Test shall be conducted by diesel injector method using the standard test conditions (30 cycles)
Clutch Test Friction Properties (JASO T 903:2016(Annex A))
|Dynamic Friction Index (DFI)||≥1.35 and ≤2.50|
|Static Friction Index (SFI)||≥1.45 and ≤2.50|
|Stop Time Index (STI)||≥1.40 and ≤2.50|
Note : MA, MA2 and MA1 shall be within the respective ranges described in the table above for each of the three indices (DFI, SFI, and STI).
Submitter may On-File register an oil which satisfies the MA specifications as a MA, MA1 or MA2 oil depending on the indices specified and marketing requirements.
The significance of the indices:
|Dynamic Friction Index (DFI)||Measure of clutch feel and how progressively power transfers during clutch engagement|
|Static Friction Index (SFI)||Measure of closed clutch pack torque handling capacity – resistance to clutch slip under high-torque “break-away” conditions|
|Stop Time Index (STI)||Measure of how quickly the clutch engages|
For more information on JASO MA, contact your Lubrizol representative.