Motorcycles have a transmission built into the engine, and the lubrication of the engine and transmission is done with the same oil. The clutch is also immersed in oil, so if you do not use motorcycles oil, there is a possibility that the clutch will slip. Also, it is not recommended to use motorcycles oils in four-wheeled vehicles. Because the structure of the engine is different between motorcycles and four-wheeled vehicles, the design of the oil is also different.

2-stroke engines require special oil performance because they burn oil together with fuel. For this reason, engine oil for 4-stroke engines cannot be used in 2-stroke engines. The reverse is also not allowed.

In motorcycles, the clutch is immersed in engine oil, so it is necessary to match the friction coefficient of the oil to the vehicle. If the friction coefficient is too low, the clutch may slip, causing problems in driving.
There are three types of JASO standards:
MB: Has a low friction coefficient and is used for low-power vehicles such as scooters.
MA1: Has a higher friction coefficient than MB.
MA2: Has an even higher friction coefficient than MA1. It is intended for high-performance vehicles with high power.
In addition, the oil test since 2023 became stricter because the fuel efficiency and exhaust gas tests have been required.
If "JASO MA2 2023" is written on the package, the oil is approved for the latest test. HKS "SUPER MC RACING" is fully approved and registered with JASO (https://www.jalos.or.jp/onfile/jaso_j-2.htm).

10W-40 uses high-performance synthetic oil, and it is an excellent oil. However, 5W-40 replaces the base oil with PAO and ester to achieve ultimate performance. With a high viscosity index, the fluidity at low temperatures and the oil film strength at high temperatures perform very well. High performance equals high-priced raw materials, so the price will be higher. Please choose the oil depending on your demands and driving situation.

In small displacement engines, high RPMs are often used and the amount of engine oil is also small, which leads to rapid deterioration. It is recommended to change the oil every 3,000km. If you drive usually in high RPMs, wear particles and blow-by gas can also be a problem. Regardless of the mileage, changing the oil as soon as possible will help to maintain good engine condition. It is also recommended to change the oil regularly every 6 months or so. Even if the mileage is short and you don't drive for a long time, the oil will also deteriorate over time by absorbing moisture from the air and oxidizing.