How Often Should You Change the Oil After Buying a Car?

[StChristopher]

After purchasing a car, the oil should be changed every 5,000 to 10,000 kilometers. Engine oil consists of base oil and additives, with the base oil being the main component that determines the fundamental properties of the oil. The functions of engine oil are: 1. To alleviate friction and high temperatures; 2. To reduce gas leakage and prevent external pollutants; 3. To prevent contact between water, air, acidic harmful gases, and parts; 4. To buffer the pressure rise in the engine cylinder port. Methods for selecting engine oil include: 1. The oil should be clear in appearance with a sulfur content of less than 1.0%; 2. The weight of residual carbon content should be less than 1.0%; 3. The volume of water and sediment should be less than 0.1%; 4. The weight of ash content should be less than 0.3%.