Can engine oil last 15000 km?

Regarding the question of whether engine oil can last for 15,000 kilometers, a comprehensive assessment should be made based on the oil type and vehicle operating conditions. Fully synthetic oil can theoretically support a 15,000-kilometer replacement interval under ideal conditions, but practical applications require careful consideration. The standard replacement intervals for mineral oil and semi-synthetic oil are 5,000 kilometers and 7,500 kilometers respectively. Although fully synthetic oil is nominally rated for 10,000 kilometers, the following stringent conditions must be met: prolonged steady-speed highway driving, no frequent start-stop cycles, stable ambient temperatures, and absence of dusty or humid environments. Turbocharged models or high-load driving (such as frequent heavy loads or hill climbing) should still adhere to the 10,000-kilometer upper limit, with potential reduction to 8,000 kilometers under extreme road conditions. The oil blotter test method is recommended for supplementary evaluation—if the oil sample exhibits distinct sediment rings or disappearance of diffusion rings, immediate replacement is required. Notably, most manufacturers' warranty policies maintain 10,000 kilometers as the maximum interval for fully synthetic oil changes, and exceeding this mileage may void warranty coverage.