The specific oil change interval needs to be determined based on a comprehensive assessment of the oil type and operating conditions. For mineral oil, It is best to change it every 6 months or 5,000 kilometres (whichever comes first). Semi-synthetic oil can be extended to 7-8 months or 7,500 kilometres, while fully synthetic oil is recommended to be changed every 12 months or 10,000 kilometres. If the vehicle is frequently driven for short trips (one-way < 5 kilometres), in long-term traffic congestion, or in high-temperature and dusty environments, the interval for fully synthetic oil needs to be shortened to 8,000-9,000 kilometres or 10 months, and mineral oil needs to be changed earlier to 4,000 kilometres or 5 months. Turbocharged models, due to their high operating temperatures, are advised to use fully synthetic oil and have it changed every 8,000-10,000 kilometres. For vehicles older than 5 years, the interval for semi-synthetic oil may need to be reduced to 6,000 kilometres due to potential engine wear. In addition, if the vehicle has been parked for more than 3 months, the oil, which has oxidized and become ineffective, needs to be changed even if the mileage has not been reached. Car owners can judge the oil condition by observing its colour (dark black and dull), texture (abnormal viscosity), or using a test strip (blurred diffusion of the oil ring). The specific interval can be adjusted by referring to the vehicle manual and combining it with actual road conditions.
