Can you use car oil in a motorcycle? Car and motorcycle engine oils are not necessarily interchangeable. However, you may use car oil in your bike, but it must meet the engine specifications.

Note: This article explains what you should know regarding vehicle oil in a bike using simpler terms.

A typical motorcycle uses a wet clutch, meaning that engine oil circulates in the clutch assembly, transmission, and engine. A car, however, uses separate reservoirs for the engine and transmission, so dry clutches do not become wet.

Moreover, a modern car motor oil contains friction-reducing compounds that are not OK with a wet clutch. These compounds can make the clutch slip; thus, malfunctioning or degrade faster.

Is there a difference between motorcycle oil and car oil?

There is no vast difference between a motorcycle and car oils. However, some key differences ensure optimal motorcycle operation. First, let’s consider the transmission cooling function of motor oil. A typical car transmission is lubricated by ATF (Automatic Transmission Fluid), and it contains the required frictional properties for optimal transmission operation.

In a motorcycle, motor oil with a different friction modification level, compared to a car engine oil, provides better transmission performance regarding slippage and transmission lock-up instead of lubricating the transmission. In essence, motorcycle oil does not use friction modifiers present in car motor oil. Secondly, motorcycle motor oil tends to break down viscosity faster than a car.

Do motorcycles need special oil?

Yes, a motorcycle needs special oil because the manufacturer would have tested before specifying what oil is best for your motorcycle. Nonetheless, a motorcycle does not necessarily need special oil because a good quality multivehicle oil is okay. The biggest concern is the viscosity for the temperature range. Ensure to check conventional automotive oils with API rating SJ or higher. Such oils may contain additives designed for high-revving and water-cooled plain-bearing motors in cars and not bikes.

Can You Use Car Oil in a Motorcycle?

Unusually, yes, but ensure that the motor oil does not use the “energy conserving” label in the API rating. Energy conserving means additional additives, which can damage your clutch.

According to Castrol, passenger car motor oils contain friction modifiers which could lead to slipping and acceleration loss in a motorcycle.

Conventionally, you can’t use car oil in a motorcycle. The motor oil you use must match the bike manufacturer’s recommendation. You would find grading on the oil packets, such as 5w-15, which indicates the oil viscosity at different temperatures. For instance, a diesel car runs at a high temperature and requires a more viscous oil. At a higher temperature, oil viscosity reduces, which requires a more viscous oil. Compared to a car, a motorcycle engine produces less temperature. Therefore, using a car engine oil, especially with the energy-conserving label, affects the oil flow in the engine area, which can degrade or damage the engine.

Moreover, motorcycle engines and car engines are designed differently. A car engine contains a gearbox and clutch in separate units, while the clutch assembly, gearbox, and crank in most motorcycles stay in one chamber known as a crankcase. There is also an exception with the Royal Enfield motorcycle, though. So, when you use car oil in the motorcycle, it lubricates the engine, the gearbox, and clutch assembly. A motorcycle clutch requires friction, which is why motor oil manufacturers add friction modifiers for optimal operation. It also maintains clutch friction and prevents clutch slip.

What if you put car oil in your motorcycle by mistake?

People mostly overstate the dangers of using car oil in a motorcycle. If you use car oil on a motorcycle by mistake, you can drain it and refill it with the recommended oil.  Also, you can ride the bike a few more miles with the wrong oil to buy new oil, and it will not damage your engine instantly. You can also use a car motor oil in a motorcycle until the next oil change interval.

Yes, using the wrong car oil in a motorcycle result in clutch and transmission issues, but it is a cumulative problem. I.e., if you use automotive oil in a bike always, it degrades the clutch and transmission over time. Slipping can create heat, which causes clutch failure. Nonetheless, the clutch plates can take a bit of heat for a short time. So, using the wrong or car oil in a motorcycle once or twice does not damage the engine instantly.

Make sure to check the owner’s manual for motorcycle oil certifications to buy.

What happens if you put the wrong oil in your motorcycle?

For Engine Oils Recommended in Relation with the Outside Temperatures (°C)

What happens if you put the wrong oil in your motorcycle depends on how often and what type of motor oil you use. For example, if the owner manual reads 10w30 and you use 15w30, no problem, but do not make it a habit. However, if you used a 20w50 motor oil, which is far from the manufacturer specification, it results in the engine degrading quickly. Some component functionalities will reduce, making it difficult for the bike to operate optimally.

The higher the oil number, the harder it is for your motorcycle to pump because they remain thicker in hot temperatures. It also increases oil pressure and decreases oil flow. However, when the oil number is too low, the oil becomes thinner, and there may not be enough lubrication to prevent metal contact when hot.

What oil should I use for my motorcycle?

The motor oil to use for your motorcycle is the oil recommended by the motorcycle manufacturer. Note that the specification may not necessarily be the same with the motor oil you can use for your motorcycle, but there should be similarities, even if it’s a car motor oil. Also, avoid energy conserving motor oil.

Meanwhile, if you are most interested in performance, use synthetic motor oil because hard riding generates high temperatures. Synthetic oil is designed to withstand breakdown at extreme temperatures. If you drive calmly, mineral oil is okay for good operation.

Final Thoughts

It is not exactly dangerous to use car oil in a motorcycle. However, you must not use car oil, especially that does not meet the motorcycle spec, habitually.

The rule of thumb is to use manufacturer-recommended motor oil grade. Manufacturers typically perform extensive bench testing to determine the optimal oil grade for a motorcycle engine following its operating parameters. Meanwhile, can you use car coolant in a motorcycle?