Is it okay to change oil every 20,000 km?

Whether the oil change interval can be extended to 20,000 kilometres requires comprehensive consideration of oil type, engine operating conditions, and driving habits. Fully synthetic oil can theoretically support intervals of 10,000 to 15,000 kilometres, but scenarios like turbocharged engines, high-temperature and dusty environments, or frequent short-distance driving accelerate oil degradation, warranting shorter intervals of 8,000-10,000 kilometres. Mineral and semi-synthetic oils require more frequent changes (5,000-7,500 kilometres). Note that prolonged use of degraded oil leads to loss of lubricity and abnormal engine wear. Always prioritize the vehicle manual's maintenance guidelines and inspect oil condition every six months to ensure engine health.