What does 10w30 engine oil mean?
2 Answers
In 10w30 engine oil, the 'w' stands for winter, '10' indicates the oil's cold start performance—the smaller the number, the better the oil's cold resistance. '30' represents the oil's kinematic viscosity standard at 100 degrees Celsius. The functions of engine oil are: 1. To separate the surfaces of relatively sliding parts, thereby reducing wear; 2. To carry heat back to the oil tank and then dissipate it into the air, helping the radiator cool the engine; 3. To circulate carbon deposits, sludge, and worn metal particles from engine parts back to the oil tank, flushing away dirt generated on the working surfaces of parts through the flow of the lubricating oil. Signs that engine oil needs to be changed include: 1. Checking the oil's viscosity—if it has no viscosity, the oil needs to be changed; 2. The oil's color turns black; 3. Excessive black particles, metal shavings, or carbon deposits in the oil; 4. The oil's smell is off.
That 10W30 oil, which I've been using for so long in my own car, is a viscosity grade for engine oil. The 'W' stands for Winter, and the number 10 indicates low-temperature fluidity—the smaller the number, the better it flows in cold weather. The 30 represents high-temperature viscosity, with higher numbers offering better engine protection under heat. For example, in harsh winters, it quickly lubricates to prevent dry starts that can damage the engine, while in summer under heavy loads, its moderate viscosity avoids overheating and wear. This viscosity is versatile, suitable for most climates, unlike more extreme grades like 5W-30 or 20W-50, balancing easy starts and durability. Choosing oil depends on the owner's manual recommendations and local temperatures: colder regions benefit from lower numbers like 10W, while hotter areas need higher ones like 40W. Regular oil changes save money by preventing major repairs—remember to check every 6 months or 5,000 km. Overall, it's practical, simplifying routine maintenance and keeping the engine cleaner longer.
