1. Based on vehicle characteristics, load, speed, etc.
2. Select oil based on recommendations from car manufacturers.
3. Based on engine usage.
4. Select oil products with a quality level higher than the requirements.
5. Generally, 15W/40 oil can be used year-round in areas south of the Great Wall.
6. If the engine is used for a long time and there is some wear and tear, choose oil with higher viscosity to prevent insufficient oil pressure