What is the difference between 5w20 and 5w30 engine oil?
2 Answers
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.
I've used both types of engine oil many times. The 5W20 feels smoother when starting the car in cold weather, like being able to drive right after starting the engine on a winter morning, thanks to its better low-temperature fluidity, and it also offers slightly better fuel efficiency. However, during long highway drives in summer when the engine is under heavy load, 5W20 might be too thin, providing less effective cooling compared to 5W30, and sometimes the engine noise feels louder. 5W30 is more stable under high temperatures, with slightly higher viscosity offering better protection for engine components, especially suitable for older cars or those frequently carrying heavy loads. But don't just focus on the numbers; it's advisable to check your vehicle's user manual. Most new cars recommend 5W20 for fuel efficiency, while older cars might be safer with 5W30. Simply put, choose based on your environment and vehicle condition, and avoid switching brands arbitrarily to prevent affecting engine lifespan. It's best to consult a professional to avoid unnecessary repair costs.
