What is the difference between 5w30 and 5w20?

[DeOscar]

The difference between engine oils 5w20 and 5w30 mainly lies in their high-temperature viscosity. 5w20 has lower viscosity (between 5.6-9.3), which is relatively more fuel-efficient and provides a lighter driving feel; while 5W-30 has higher viscosity (between 9.3-12.5), which is relatively more fuel-consuming and makes the throttle feel heavier, but results in quieter engine noise. Below are the relevant explanations: 1. The meaning of 5w30 engine oil: The 5W in 5W-30 indicates the cold-start performance of the oil. Using oil with a lower number before the W makes it easier to start the engine in cold weather. The 30 in 5W-30 indicates the oil's viscosity characteristics at high temperatures. Higher viscosity oils (with higher values) may be more suitable for high-speed driving or heavy-load vehicles. 2. The meaning of W: The number before the W represents the oil's viscosity at low temperatures—the smaller the number, the higher the viscosity and the better the protection. The number after the W refers to the oil's viscosity grade at 100°C—the larger the number, the higher the viscosity.