How many kilometers should a private car change its oil?

[DeLaila]

Generally, mineral oil must be changed every 5,000 kilometers, while fully synthetic oil can last up to 10,000 kilometers before needing a change. This refers to the type of oil. Another factor is usage time; typically, oil should be changed every six months. If the car is driven less frequently, the oil change interval can be extended slightly. The functions of engine oil are as follows: 1. Lubrication: The primary role of engine oil is to lubricate the engine's pistons, bearings, and other components, providing protection. 2. Sealing: After the engine is coated with oil, it helps seal during the "power stroke," preventing high-temperature, high-pressure gases in the combustion chamber from leaking into the crankcase through gaps. 3. Heat dissipation: When the engine operates at high speeds, various components generate heat due to friction. This heat is carried away by the circulating oil to the oil cooler and dissipated into the air. 4. Rust prevention: Besides lubrication, engine oil effectively prevents metal parts from rusting and corroding. 5. Cleaning: Impurities and metal wear particles produced during engine operation are filtered out by the oil filter, keeping the lubrication system clean.