What is the difference between 5w30 and 10w40?
2 Answers
The differences between 5w30 and 10w40 are as follows: 1. Different viscosity. The number after the letter W indicates the viscosity characteristics of the oil at high temperatures. 10w40 oil has a higher viscosity than 5w30. High-viscosity oil may be more suitable for high-speed driving or heavy-duty vehicles. 2. Different low-temperature fluidity. Oil starting with 5w has better low-temperature fluidity and can be used in colder regions. Oil starting with 5w can cope with environments above minus 30 degrees Celsius, while 10w can only be used in environments above minus 25 degrees Celsius.
I also struggled with these two types when changing my engine oil. Simply put, the number before the W represents low-temperature fluidity; 5W has better low-temperature fluidity than 10W, providing more timely engine protection during cold starts. The number after W indicates high-temperature viscosity, with 30 being slightly thinner than 40 at high temperatures. Since I live in the north where winters are quite cold, I chose 5W30 for quicker starts and better fuel efficiency, and my car has been running smoothly for 70,000-80,000 kilometers. 10W40, with higher viscosity, is more suitable for older cars or those frequently running at high RPMs, offering better sealing but slightly higher fuel consumption. It's important to choose based on your driving environment.
