JASO MA1

Overview

JASO MA1 oils are formulated for use in four-stroke motorcycles and scooters and are primarily suitable for wet-clutch applications.

The main physical, chemical and clutch frictional requirements, according to the current version of the standard (JASO T903:2023), for JASO MA1 oils are shown below:

Physical and Chemical

Requirement	Methods	Unit	Limit
Sulphated Ash	D874/JIS K 2272	% mass	1.2 max.
Phosphorus	D4951/JPI-5S-38	% mass	≥0.08 and ≤0.10
Molybdenum	D4951/JPI-5S-38	ppm	Report
Foaming Tendency
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)		% mass	15 max.
Shear Stability (Kinematic viscosity (100°C) after test)	D5800/JPI-5S-41	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	ASTM D6278¹	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 903:2023(Annex A))

Property	JASO MA1
Dynamic Friction Index (DFI)	≥1.35 and ≤1.50
Static Friction Index (SFI)	≥1.45 and ≤1.60
Stop Time Index (STI)	≥1.40 and ≤1.60

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 or MA1 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 MA1, contact your Lubrizol representative.