What does the engine oil grade represent?

[LaAmy]

The engine oil grade represents the viscosity and quality of the oil. The viscosity of lubricating oil is often indicated using the SAE grade, where SAE is the abbreviation for the Society of Automotive Engineers. The 'W' stands for winter, and the smaller the number before it, the better the oil's low-temperature fluidity, indicating a lower usable environmental temperature and better engine protection during cold starts. The number after 'W' indicates the oil's high-temperature resistance; the larger the number, the better the oil's protective performance at high temperatures. The oil classification is represented by a combination of two letters. The 'S' series represents oil for gasoline engines, with general specifications ranging from SA to SN. Each subsequent letter indicates better performance than the previous one, with more additives to protect the engine. The further the letter is in the alphabet, the higher the quality grade.

[DiDerek]

I saw someone asking about the meaning of motor oil grades, so I’ll share my experience. A combination like 5W-30 actually describes the viscosity characteristics of the oil. The 5W represents the winter part—the smaller the number, the better the fluidity at low temperatures, making cold starts easier for the car. The 30 indicates the viscosity at high temperatures—a larger number provides better protection for engine components. Last time, I mistakenly used 10W-40, and it resulted in difficult starts in winter and some engine stuttering. Choosing the right grade is crucial—it affects fuel efficiency, engine wear, and overall lifespan. Always check your car’s user manual and stick to the recommended grade—don’t cheap out and experiment with different grades. During regular oil changes, check to ensure it matches the season. In summer’s high temperatures, you might need a higher viscosity grade to avoid overheating issues. Routine maintenance is simple—just consult a professional when in doubt.

[AaliyahLee]

Having worked in the auto repair industry for several years, I must emphasize the importance of motor oil viscosity grades. Take the 10W-40 grade as an example: the 'W' stands for Winter, indicating cold-weather performance. The lower the number before the W, the better the oil flows at low temperatures, ensuring quicker cold starts. The number after, such as 40, represents high-temperature viscosity—higher numbers mean better protection against engine wear from overheating. Many customers mistakenly use 5W-20 in older vehicles, resulting in oil that's too thin, causing seal leaks or increased engine noise. Choosing the right grade can improve fuel efficiency by 10% and prevent costly repairs. My advice: match the oil to your vehicle's age—newer models typically use lower viscosity oils like 0W-30 for superior cold-weather performance, while older vehicles benefit from higher grades like 15W-40 for enhanced protection. Make it a habit to check the oil grade every 5,000 km and consult a dealership if needed. This practical knowledge helps car owners avoid common pitfalls.

[LeHeidi]

I've been driving for decades, so let me briefly explain the oil viscosity ratings. For example, the common 5W-30: the W stands for winter, and the smaller number 5 means the oil flows better in cold weather, making the engine easier to start. The 30 indicates good viscosity in hot weather, keeping the engine running smoothly. I remember once using the wrong grade—adding oil that was too thin in summer—and the engine shook. Now I know choosing the right grade helps the engine last longer and reduces wear. The car manual has recommendations; just follow them. Young folks shouldn't mess around with this. Keep this in mind during maintenance—it saves both hassle and money.

[LaLeo]

Engine oil grades are quite interesting, like 5W-30. The 5W part indicates cold-start fluidity—the lower the number, the smoother the engine starts in cold weather. The 30 represents the oil's ability to maintain stable viscosity at high temperatures, protecting the engine from stuttering. Modern vehicles, including electric cars, also have specific requirements. 0W-20 is a common new grade, offering exceptional low-temperature performance. Avoid using non-standard oils, as they can increase fuel consumption or cause engine issues. I recommend referring to the manual for regular changes, opting for reputable brands, and having a professional shop check the viscosity grade. This knowledge is highly practical for maintenance, and mastering it can save you a lot of trouble.