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Buy 10W-40 Motorcycle Oil
10W-40 is the standard viscosity on motorcycles: thin enough when cold for oil pressure to build quickly, load-bearing enough when warm for a gearbox that runs in the same oil. More important than the number is the category next to it - for machines with a wet clutch, JASO MA2.
Which vehicle?
Enter your vehicle - we show only what belongs in it.
Which machines 10W-40 applies to
The majority of water-cooled road motorcycles run this grade, across all capacity classes and makes. It is the compromise that works all year round at European temperatures.
There are deviations in two directions: air-cooled engines and large twins reach higher oil temperatures and are therefore more often specified for 15W-50 or 20W-50. High-revving sports engines sometimes call for 10W-50. What counts is always the handbook for the specific machine, not the design in general.
Why shear stability matters here
On a motorcycle the same oil runs through the gearbox. The gears shear the viscosity index improvers in the oil mechanically, and an oil with a weak additive package loses viscosity over its service life as a result: a 10W-40 effectively becomes a thinner oil while the engine is loaded exactly as before.
That is why fully synthetic motorcycle oils in this grade justify their extra cost more readily than in a car engine that does not share its oil with a gearbox.
What has to be on the label
Next to 10W-40, the JASO category: MA2 for machines with a wet clutch, MB for scooters with automatic transmissions. If the JASO rating is missing altogether, the product has not been tested for use in a motorcycle, whatever car approvals it otherwise carries.
Frequently asked questions
Can I run a 10W-40 car oil in a motorcycle?
Only if it expressly carries JASO MA or MA2. The viscosity alone is not enough: car oils often contain friction modifiers that make the wet clutch slip, and they are not designed for the shear stress of a shared gearbox.
What is the difference between 10W-40 and 10W-50?
Cold-start behaviour is the same; at operating temperature the 50 carries more load. That makes sense at high oil temperatures, so with a sporting riding style or on air-cooled engines - but only if your manufacturer releases the grade.
How much oil does a motorcycle need?
Depending on the engine, usually 2.5 to 4 litres, considerably less on singles. The 4-litre packs therefore normally cover one change including the filter; the exact fill quantity is in the handbook.
