How to know if a car needs an oil change?

Determining whether a vehicle needs an oil change requires comprehensive consideration of oil type, mileage, time interval, and actual condition. Mineral oil is recommended to be changed every 5,000 kilometres or 6 months, semi-synthetic oil every 7,500 kilometres or 7-8 months, and fully synthetic oil can last up to 10,000 kilometres or 1 year, adhering to the "whichever comes first" principle. Turbocharged models are particularly recommended to use fully synthetic oil. For special scenarios like the first oil change during a new car's break-in period, replacement at 2,500 kilometres is advised. For low-temperature short trips or frequent long-distance driving, the interval should be reduced to 5,000-7,000 kilometres. Note that even if mileage thresholds aren't met, opened mineral oil exceeding 3 months or semi-synthetic oil used beyond 1.5 years should be replaced, with simultaneous oil filter replacement to maintain lubrication system efficiency. Regular maintenance following the manufacturer's manual effectively prevents engine wear. Monthly oil condition checks are recommended, with increased frequency under extreme driving conditions.