What is the difference between full synthetic engine oils 5w30 and 5w40?
1 Answers
The differences between full synthetic engine oils 5w30 and 5w40 are as follows: 1. The smaller the number before the W, the lower the viscosity at low temperatures, the better the low-temperature fluidity, and the lower the applicable minimum temperature. 2. The larger the number after the W, the higher the viscosity of the oil. The number after the W mainly refers to the oil's high-temperature resistance index. The larger the number, the better the oil's protective performance at high temperatures. Here are detailed guidelines for choosing engine oil for cars: 1. Based on vehicle age: Generally, referring to the vehicle maintenance manual, new cars should choose oil with slightly lower viscosity. As the vehicle ages, choose oil with slightly higher viscosity. Older car engines experience more severe wear, so they require oil with relatively higher viscosity for smoother and more comfortable driving. 2. Based on road conditions: Road conditions greatly affect the lifespan of the oil. In areas with poor road conditions, the oil change interval should be shortened. In urban areas with frequent traffic congestion and stops, it is recommended to use oil with lower viscosity. For frequent long-distance or high-speed driving, it is recommended to use oil with slightly higher viscosity.
