What is the difference between 15w40 and 10w40?
1 Answers
The difference between 15w40 and 10w40 lies in their low-temperature performance: 15w40 is suitable for an ambient temperature of -20 degrees Celsius, while 10w40 is suitable for -25 degrees Celsius. In 15w40 and 10w40, the 'w' stands for winter, the number before 'w' indicates the oil's low-temperature fluidity—the smaller the number, the better the fluidity at low temperatures. The number after 'w' represents the oil's high-temperature resistance—the larger the number, the better the protection at high temperatures. The function of engine oil is to lubricate and reduce wear, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption.