What is the difference between 5W40 and 10W40 engine oil?
1 Answers
The difference between 5W40 and 10W40 engine oil lies in their suitable operating environments. Here are the detailed explanations: 1. 5W40 oil can withstand external low temperatures of -30°C, while 10W40 oil can withstand -25°C. Both 5W40 and 10W40 can tolerate external high temperatures up to 40°C. This means 5W40 is more suitable for cold northern regions compared to 10W40. 2. The "W" in 5W40 and 10W40 stands for Winter. The smaller the number before W, the lower the oil's low-temperature viscosity, the better its low-temperature fluidity, and the lower the minimum applicable temperature. This results in better engine protection during cold starts. Therefore, 5W40 has a lower minimum applicable temperature than 10W40. The number 40 represents the oil's high-temperature viscosity grade. A larger number indicates stronger high-temperature viscosity, thicker oil film, and better sealing and protective capabilities. 3. 5W40 is mainly suitable for colder northern regions, energy-efficient engines with low load intensity, medium-low speeds, and small compression ratios. 10W40 is primarily suitable for warmer southern regions, mountainous areas with frequent aggressive driving and heavy loads, or vehicles that operate for extended periods, such as taxis and minivans.
