Whether changing engine oil every 3 months is normal needs to be comprehensively judged based on the type of engine oil and vehicle usage conditions. Mineral oil is usually recommended to be changed every 5,000 kilometres or 6 months, semi-synthetic oil every 7,500 kilometres or 7-9 months, and fully synthetic oil can last up to 10,000 kilometres or 1 year. If the vehicle is used under severe working conditions for a long time, such as short-distance driving (one-way < 5 kilometres), high-temperature environments, frequent congestion, or aggressive driving, the oxidation and contamination rate of the engine oil will accelerate. In this case, it is reasonable to shorten the replacement interval to 3 months, especially when using mineral oil or semi-synthetic oil. For example, in congested cities like Kuala Lumpur, frequent starts and stops will cause the engine oil to deteriorate prematurely, and dusty weather may also accelerate the mixing of impurities. Even if the vehicle has not reached the mileage after long-term parking, the engine oil that has been opened for more than 6 months (mineral oil) or 12 months (fully synthetic oil) needs to be replaced to avoid oxidative deterioration and damage to the engine.
