10W-30 vs 10W-40 Motorcycle Oil

Perhaps the two most common motorcycle oils in the world are 10W-30 and 10W-40 oils. They're very similar, but can you use either/or in your particular machine?

Watch the video above or read on below to learn about the differences between 10W-30 and 10W-40 motorcycle oils. 

Buy 10W-30 motorcycle oil

Buy 10W-40 motorcycle oil

What Do the Numbers Mean?

Both 10W-30 and 10W-40 are multi-grade engine oils, which means they carry properties of different weight oils, depending on the conditions. 

10W-30 vs 10W-40 motorcycle oil

The first grade of the motor oil is the number before the W, and the second grade is the number after the W.

10W-30 vs 10W-40 motorcycle oil first grade

10W-30 vs 10W-40 motorcycle oil second grade

Both of these oils are 10W, and the W stands for winter, not weight. They both behave as regular 10W-SAE grade oil, which means that the oil is thinner and flows quickly even when it’s cold to lubricate an engine started up on a cold day. 

10W-30 vs 10W-40 motorcycle oil winter

The second number after the W is where the slight difference is found in these oils. That number represents the oil's viscosity at temperatures above 212° F or 100° C. The higher the number, the thicker the oil is at higher operating temperatures. So the 10W-40 oil is a tad thicker than the 10W-30 oil when the engine is hot, meaning it offers a little more protection. 

10W-30 vs 10W-40 motorcycle oil viscosity

Both of these oils are good for cold starts, but if you're in a warmer climate or your engine runs a little bit hotter, the 10W-40 oil is the way to go. However, if you live somewhere colder or your machine’s engine runs cooler, the 10W-30 works better, since it runs a little thinner in cooler temperatures. 

10W-30 vs 10W-40 Fuel Economy

When it comes to fuel economy, the flow of oil adds drag inside your motorcycle’s engine. A thinner oil produces less drag, which increases fuel efficiency, so a 10W-30 oil offers better fuel economy than the 10W-40 oil. 

10W-30 vs 10W-40 motorcycle oil fuel economy

However, choosing a motorcycle oil based on whether it offers better fuel efficiency is a mistake. You should only choose the oil based on what’s best for the motorcycle’s engine and operating conditions, not fuel economy.

Can You Use Both 10W-30 vs 10W-40 Oil? 

So is it safe to use either oil in your motorcycle? Yes, but it's best to use the oil recommended by the manufacturer for your motorcycle’s conditions. Either grade will work, but you should choose a motorcycle-specific oil so that your machine’s clutch is protected. 

Can You Use Automotive Oil in a Motorcycle? 

One last thing to consider is how the oil relates to your motorcycle’s clutch. That means no automotive oil. Cars use a separate transmission fluid, but in a motorcycle, the same oil lubricates the engine, the clutch and the gearbox in most cases. 

10W-30 vs 10W-40 motorcycle oil automotive

Additives in car oils also use friction modifiers that can negatively impact the engagement of your motorcycle's clutch, so using an automotive oil in a motorcycle is not recommended. 



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