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Comprehensive Guide on Selecting Motorcycle Engine Oil

Replenishing oil in our beloved two-wheelers is an essential regular maintenance procedure if we want to keep them always on the go. If the engine isn’t well-oiled with a properly selected high-quality oil, the problems will come sooner or later, but they will definitely cost much more than the yearly oil supply. “How to select the right motorcycle engine oil?” is one of the most frequently asked questions addressed to yourmotobro.com experts. Here’s their definitive guide!

Know the Oil Types

Each oil type is made for specific uses and has particular temperature and viscosity levels to withstand certain loads. Below are the main oil types.

Mineral oils

This is a standard natural-base type that provides exceptionally good protection for new engines, especially if their capacities are below 125cc. The molecules of mineral oils don’t bond together under extreme loads. As a result, this type isn’t as long-lasting and efficient as synthetic counterparts. It’s very good for the first non-aggressive miles of your bike, but not the leads to faster engine wear-off if your style is aggressive.

Semi-synthetic oils

Due to roughly 30% of chemical components in the composition, this type is much more universal than clear crude mineral oil. It’s suitable for a wide range of engines and allows you to switch to a sporty riding style without damaging the engine. Most bikes with 125-180cc engines are factory-filled with semi-synthetic oil.

Synthetic oils

Due to its low-viscosity index, this motorcycle oil type is the best for any 200cc and higher motor. This oil has mineral components only as minor additives. This oil type is also perfect for high-performance motorbikes, tolerates high temperatures, and minimizes wear-off caused by aggressive riding. Of course, the price for this type is also the highest, but we consider it a fair fee for secure, high-performance riding.

Essential Considerations

Now that you know the main differences between the oil types, learn how to understand the deeper characteristics, such as grades, viscosity, etc.

Engine oil grades

This is perhaps the most confusing aspect of motorcycle engine oils, but it’s also highly important to understand. For multi-grade oils, the grade starts with a number (0, 5, 10, 15, 20) and letter “W” (stands for WINTER, not WEIGHT). The second number is usually from 20 to 60 with increments of 10. The lower the first number, the faster the oil flows under cold temperatures. The second number is called SAE (Society of Automotive Engineers) and defines oil resistance to flow (viscosity) at 100°C through a standard aperture. Thicker oils have a higher number and vice versa. Check out the needed numbers in the motorbike manual, and mind that the numbers can be different for various parts of the world.

Viscosity index

In simple terms, the viscosity index defines the thickness, stickiness, and consistency of the oil. The lower this index is, the faster the oil flows within the engine. Logically, lower-viscosity oils are what you need for high-performing motorcycles. As you have already understood, mineral oils have higher viscosity indexes and cannot provide the needed lubrication quality for motors above 125cc if they are exploited on high RPMs frequently. Remember that poor lubrication can lead to metal-to-metal grind, decrease motor efficiency, and cause faster wear-off. You still have to match this index to your motor, as a high index isn’t always bad.


Today, additives are a common component of motorcycle oil to neutralize acidity and make oils clearer. Additives can help the motor to stay cooler, last longer, and clear itself from harmful carbon formations on various active and passive parts. It’s desirable to avoid disassembling the motor for as long as possible, right?


No matter which country you live in, it has its own compliance requirements to oil manufacturers. The compliance standard is always highlighted on the oil can in order to keep you aware of the strict standards maintained during the manufacturing cycle of the product. Knowing about the compliance, you can make sure that the oil breed meets the original equipment manufacturer (OEM) requirements. That’s perhaps the only way to know whether you can trust the brand. Look for something like ”The American Petroleum Institute” (API), SAE, or the Japanese Engine Oil Standards Implementation Panel (JASO). In the vast majority of cases, the oil is compliant with the regional requirements, but checking out OEM compliance is still necessary.

Riding style

Average everyday commuting on a scooter or a low-cc motorbike requires natural or semi-synthetic oils, depending on the factory recommendation. Both options are more affordable than their fully synthetic counterparts and provide just the right amount of care under normal conditions.

If your choice is to “put the pedal to the metal” or explore tough terrains, low-viscosity synthetic oils are a must for your bike. This will let you reach peak performance and achieve an overall performance boost. The motor will work as it’s meant.

Manufacturer recommendations

Every self-respecting manufacturer highlights the recommended oil characteristics for every engine that comes from the line. It’s wise to adhere to the official recommendations as every trusted brand tests its engines thoroughly before giving the green light to new makes. They simply know the capabilities of their motors better than anyone, so you can trust their words. If your motorcycle engine is custom, the mechanic will provide you with all the needed information.

These rules work at least for the first 6 months of riding. This is quite enough for any engine to reach the best condition. After that, you can flush it and switch to the oil that suits your style the most. You can rely on the knowledge you have got from this guide.

Replenish on Time

Now that you know how to choose the right oil, make sure to figure out the appropriate service intervals for your machine. Always stick to the recommended mileage, check oil levels with a dipstick, and stay tuned to us and yourmotobro.com for more useful info on motorcycle care!

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