Should You Use 30 or 40 Weight Oil in Summer?

[OMarcus]

In summer, you can also choose 5W-30 oil, but you must select oil with higher viscosity. Engine oil is mainly distinguished between winter and summer use based on its viscosity grade, commonly known as the oil rating. The low-temperature fluidity of the oil is the basis for classifying winter oils, with 0W, 5W, 10W, 15W, 20W, and 25W all indicating winter oils. The viscosity grade at 100°C is the main reference for summer oils, with viscosity grades of 20, 30, 40, 50, and 60 at 100°C all being summer oils. The differences between 5W-40 and 5W-30 oil are as follows: 1. Different oil viscosity: 5W-40 oil has higher viscosity than 5W-30 oil. 2. Different oil fluidity: 5W-40 oil has relatively poorer fluidity compared to 5W-30 oil. 3. Different high-temperature resistance: 5W-40 oil provides better engine protection at high temperatures than 5W-30 oil.