Can I put car oil in my 4-stroke motorcycle? Yes but.. (Fully Explained)

Should you put car oil in 4 stroke motorcycle engine
Should you put car oil in 4 stroke motorcycle engine

Most four-stroke engines use oil in the same way whether it’s a car, motorcycle, or truck. Nowadays these 4-stroke motorcycles and cars have engines with similar cooling systems. And, the engine oil used in them has identical viscosity grades. So what the difference between car and motorcycle engine oil. In the end, “Can you use the car oil in your 4-stroke motorcycle?” After talking to some specialists and doing some research here is what is found.

So, Can I put car oil in my 4 stroke motorcycle engine? You can use car oil in your 4 stroke motorcycle engine unless the car oil says “energy conserving” on the label and your motorcycle has a wet clutch in it. The safest and right option will be to follow your owner’s manual recommendation for your motorcycle oil change.

Now, if you got confused by the term “energy-conserving”, then this definition will help you.

The Engine oils categorized as energy-conserving are developed to enhance the fuel economy of passenger cars, vans, and light-duty trucks. These oils have produced a fuel economy improvement of 1.5 percent or greater over a standard reference oil in a standard test procedure.

So, what’s the problem of using energy conserving in motorcycles?

The reason you should not put “Energy conserving” oils in your motorcycle because it makes the wet clutch slip. The wet clutch in a motorcycle engine fully immersed in the car engine oil can damage it because if the clutch slips it builds up a lot of heat and will warp the steel disks and you may have to replace them.

Oil does several things like cleaning and preventing wear and tear and many more in the motorcycle engine. That’s why engine oils are made vehicle and engine specific. 

Thus, you can use car engine oil to put in your four-stroke motorcycle engine if the label doesn’t say it energy conserving and your motorcycle have wet cutch it in.

Pick up a high-quality oil that meets the basic requirements found in your owner’s manual. It needs to be incorrect viscosity range and avoid any oil with energy-conserving on the label.

Difference between car and motorcycle engine oil

Engine oils are formulated differently for both motorcycles and cars. Although, these 4-stroke motorcycles and cars have engines with a similar cooling system. So, what the difference between the car and motorcycle oil? Let’s discuss the difference between the car and motorcycle oil.

The main difference between the motorcycle and car engine oil is the lubrication system. Because in motorcycle the same oil is shared between the engine and gearbox while in the car engine and gearboxes get separate oil with different lubricant.

Additives are added to the oil to reduce friction for the more efficient working of an engine. This works fine for car engines because of separate oil use. But in a motorcycle excess friction modifiers can make the clutch lose. You may expect to clutch slippage to occur using a car engine oil in your motorcycle.

Car engine oil contains a friction modifier, and its main goal is reducing friction between moving parts to provide good fuel economy and efficiency. These vehicles don’t have to worry about clutches cause their clutches are exterior. Apart from these, car oil also contains additives like detergents to keep the engine clean who ash is relatively high.

As car oil contains detergent, if used in motorcycles it could result in the formation of deposits on the piston crowns as well as the valve train. Detergents are the main cause of pressure build-up which will cause perforation and burning on the components. Thus, you should stay away from car oil.

As Motorcycle uses the same oil for both the engine and the gearbox. Therefore motorcycle oils are uniquely formulated to offer the highest possible protection to engine components and gears. The reason you should not use car oil in a motorcycle is that the motorcycle engine oil needs to lubricate the wet clutch, thus it requires balance friction modifiers. If the friction level gets imbalanced then the clutch will cause slippage.

Even oil companies accept that motorcycle engines are one of the most difficult environments for engine oil to perform. The compact space has its own restrictions on the cooling system and you will also observe that a general rpm of a motorcycle is higher than cars.

Engine oil molecules in the running motorcycle engine are always under higher pressure and stress situation which breaks down the oil and bring down the viscosity.

Hence motorcycle engine oil is copolymer-based and other advanced viscosity modifiers to keep and hold the multi-grade viscosity even under heavy use.

This should be clear that even if your motorcycle has a dry clutch or separate gear oil a car oil won’t last long and give the motorcycle its optimum performance.

What do the numbers (10W-40) mean on the oil mean?

What does numbers mean on engine oil?
What do numbers mean on engine oil?

When you go to buy engine oil either online or offline, you may see some numbers like 5W-30, 10W-40 on the label. So, what does this number say about engine oil? Let’s see.

These are numbers to represent the viscosity and thickness of the fluid. The number before the W describes the oil at low temperatures. The “W” stands for “winter”, the number behind it describes the oils viscosity (or thickness) in winter times or say low temperatures. The number succeeding “W” indicates the viscosity at higher temperatures.

In short, the numbers on the oil label just represents the viscosity (thickness) of the oil where W stands for Winter.

These numerical codes were established by SAE (Society of Automotive Engineers) for grading motor engine oils according to their viscosity characteristics. The viscosity of oil changes with a change in temperature. That’s why you generally see something like this printed on the oil label: SAE 10W-40.

So, an oil rating 10W-40, here the number 10 before “W” represents the viscosity of oil in winter (at low temperature). The lower the number, the thinner the oil and the better the start performance in cold. As it helps the engine to start even at very low temperatures (in the winter season). The number 40 after the W describes the thickness of oil at the engine’s higher temperature.

That’s the reason you must choose the right viscosity grade engine oil for your motorcycle, thus follow your service manual.

Can I put car oil in motorcycle engine?


Avoid any car oil if your motorcycle has a wet clutch and the oil says “energy conserving” on the label. Apart from this there some other reasons like friction modifier and detergent in the car oil that makes it unsuitable for a motorcycle engine. For the long life of your motorcycle engine make sure to use oil specified in your service manual. Although, if needed you can use car oil it will not harm but for longevity and performance go with motorcycle-specific oil recommended by the service manual.


Can you mix motorcycle oil with car oil?

Car oil contains a friction modifier that is bad for motorcycle engines with a wet clutch. Thus mixing both oils may result in some components that may be bad for your engine and becomes unsuitable for car and motorcycle both

Thus Mixing car oil and motorcycle oil is a bad idea because both have some engine differences. There are many additives in the oil to improve lubrication for an engine that may react with motorcycle oil negatively and harm the engine.

Can you use automotive oil in a motorcycle?

You should not use automotive oil in a motorcycle as it contains friction modifiers and is formulated with the aim of reducing friction between moving parts to provide fuel economy and efficiency in cars. Thus using the oil in a motorcycle can result in the formation of a deposit on the piston crown as well as valve train.

The best and safest thing to do is using recommended oil for your motorcycle in your service guide.

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