What is the difference between 5w20 and 5w30 engine oil?

[ReedLynn]

The main difference between 5w20 and 5w30 engine oil lies in their high-temperature viscosity. Relevant information about engine oil viscosity is as follows: 1. For 5w30 and 5w20 engine oils, the number after 'W' represents high-temperature viscosity. Higher viscosity provides better sealing performance. However, bigger numbers aren't always better because higher viscosity also means greater friction, resulting in more engine power loss. 2. Viscosity is one of the most important characteristics of engine oil. Generally, the property of 'oil' is that it thickens at low temperatures and thins at high temperatures, which runs counter to actual engine requirements. Additives can be used to alter this inherent property of oil. 3. The higher the oil viscosity, the more fuel the engine consumes and the louder the noise becomes, but the better the sealing performance will be.