Can I Use 10w40 Car Oil in My Motorcycle?

When it comes to using 10w40 car oil in your bike, it will be a big ”No” from our side. Experts have highlighted this point multiple times that car motor oils negatively impact the bike’s performance. It only lubricates the bike’s engine and not the clutch and the rest of the transmission system.

So, the commonly asked question is: Can I use 10w40 car oil in my motorcycle? The answer is ”NO”.

You should only use motorcycle-specific oils. Such oils efficiently oil the engine and lubricate the transmission and the wet clutch. On the other hand, car motor oils just lubricate the components of the bike’s engine. The rest of the details are mentioned below; you can check them out:

Is it OK to use 10w40 car oil on your bike?

As mentioned, it is a complete ”no” if you plan to use 10w40 car oil on your bike. If you want to maintain your bike’s performance, engine power and the rest of the components’ capability, then never and ever use car oil.

Especially in the case of vehicles, specific oils should be used. If it is a car, go with the car-specific oil; if it is a bike, use the motorcycle-specific oil. Fulfilling this requirement will let the vehicle function properly and at its best. If, by mistake, you add car oil to your bike’s engine, the immediate thing that you have to do is to flush the system.

What happens when you add 10w40 car oil to the motorcycle?

Your bike will encounter heavy risks if you ever make a blunder of adding 10w40 car oil into your motorcycle:

  • Car oil only lubricates the bike’s engine, not the transmission and clutch system.
  • It does not correctly lubricate and oil your bike’s pistons, bearings and valve train.
  • The car oil does not provide enough lubrication, which is why the bike gets overheated, and its parts start to cause so much friction.
  • The gears in the transmission will wear and tear down faster.
  • Your bike will likely witness major transmission issues if you use 10w40 car oil.
  • The car engine oil is usually and generally packed with anti-friction additives. Using this oil in your bike will push its clutch plates to slip, thus risking the rider’s life and compromising the transmission system’s power.
  • The engine might become inefficient and completely damaged with time.

What is the right oil to use on a motorcycle?

Motorcycle-specific oil should be used in bikes. Grabbing any oil bottle will only be detrimental and super-destructive for your bike. In addition, the oil bottle you have chosen should have a picture of the motorcycle. That is a clear indication that you have picked the right engine oil.

Remember that each bike needs a specific viscosity of oil. The vehicle cannot drive smoothly if the viscosity is high or low. You need to determine beforehand and analyze properly what oil type your bike needs. Read the oil cap and go through the owner’s manual; it will help you decide whether it is the right oil for your motorcycle.

What do we mean by viscosity in a motorcycle oil?

All oils, whether for engine, transmission or motor, are usually described by a grade. A typical example is 10W-40. Society of Automotive Engineers has developed these motor oil grades and scales.

Viscosity means the ”thickness of oil” and how much it is resistant to flow. The general rule is that the higher the viscosity, it means that the more viscous and thicker the fluid will be. If the viscosity is lower, oil can flow easily.

If the viscosity comes out to be low, it will get tough for the oil to lubricate the fast-moving parts of the engine, ultimately contributing to friction and increased wear and tear. Too high viscosity, the oil will not reach the upper cylinder piston walls, resulting in wear and tear.

Types of oils for motorcycles

Below, we have discussed the details of three types of motorcycle oils:

Mineral oil

Mineral oil, or MO, is commonly used in bikes. It is the primary and traditional oil that is suitable to be used for smaller-capacity motorcycles. Furthermore, you can use this oil option if your bike has a small engine. It is an affordable type, too.

Semi-synthetic oil 

Semi-synthetic oil is a blend of mineral and full synthetic oil. It is recommended for bikes with a smaller engine capacity and is ideal for daily commuting.

Fully synthetic oil 

Fully synthetic oil is highly recommended for high-performance motorcycles. The common examples are race machines and superbikes. Being the highest quality oil, you will find it comparatively expensive.

The basic difference between a car and motorcycle oil

We know that cars and motorcycles function more or less similarly. But there exists a contrasting difference between the engine oils you use. In other words, their engine oils differ in terms of engineering and composition.

Motorcycle engines can get hotter than car engines. It is the main reason that the components of bike engines are more vulnerable to wearing and breaking down. To tackle these issues, bike engine oils have better lubricity properties. Besides, they are more capable and improved in withstanding heat, severe temperature conditions and high RPMs.

The motorcycle engine and its transmission are interconnected. They need the same kind of oil for lubrication. In the same way, a car engine and its transmission are connected, too, but they require separate kinds of oils. You cannot use the car engine oil in the car’s transmission. Lastly, car engine oil lacks the extra friction additives as well as lubrication properties.

The relation between using the correct engine oil and the bike performance

Experts have noticed a solid relationship between using the proper engine oil and the bike’s performance.

It does not matter whether you are a commuter, weekend rider, or racer; using the right engine oil in your bike is a must. It has the biggest and most noticeable influence on your bike’s speed, longevity, operations and performance.

The right oil lets your bike spin up to 15000 revs with ease. The internal components of the four-stroke engine and the clutch and transmission function incredibly. Each bike part stays protected and completely shielded using the right oil.

Thus, the correct lubrication maximizes engine performance and minimizes friction, reduces pumping pressures, and prevents the formation of harmful deposits onto the bike.



So, coming to the concluding part of the discussion! You must use motorcycle-specific oils if you have a bike.

If you do not want to pose a risk to your bike’s engine, clutch or transmission system, then use the right oil. You can share with us if you have ever used car oil on your motorcycle and what results you got; stay connected!

About Paul Lavery

Hey everyone, this is Paul Lavery! I've been passionate about automotive and motorcycle culture for as long as I can remember, and I'm excited to bring my diagnostic expertise to you. My articles aim to explore every aspect thoroughly, but if you ever need additional information, don't hesitate to drop a comment or reach out to me directly. Let's dive into the world of engines and gears together!

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