What Do the Numbers on Motorcycle Oil Mean?
2 Answers
Motorcycle oil grades are established by the Society of Automotive Engineers (SAE) to measure the viscosity of lubricating oil at different temperatures. Motorcycle summer oil grades: 20, 30, 40, 50. The higher the number, the greater the viscosity and the higher the maximum applicable temperature. All-season oil grades are: 5W/20, 5W/30, 5W/40, 5W/50, 10W/20, 10W/30, 10W/40, 10W/50, 15W/20, 15W/30, 15W/40, 15W/50, 20W/20, 20W/30, 20W/40, 20W/50.
The grade of motorcycle oil mainly indicates the viscosity level, such as the common 10W-40. The number with a W in front represents winter fluidity—the smaller the number, the easier it flows in cold conditions. The number after indicates high-temperature viscosity—the larger the number, the better it resists heat and protects the engine. I've been riding motorcycles for over a decade, and my personal experience tells me that choosing the wrong grade can be dangerous. Using low-viscosity oil in summer caused the engine to overheat and wear out faster, while in winter, the bike wouldn't start, delaying my trips. Now, I strictly follow the owner's manual and choose oil based on the recommended grade to avoid problems affecting safety. During daily rides, I also pay attention to climate changes—opting for 5W-30 in cold regions to ensure smooth starts and 15W-50 in hot areas to prevent overheating. I've developed the habit of checking the condition of used oil and replacing it immediately if any abnormalities are found, which saves both hassle and money.