How often should engine oil be changed if the car is not driven much?
2 Answers
If the car is not driven frequently, the engine oil should be changed every six to eight months. Here is an introduction to engine oil: Classification of engine oil: Automotive engine oil is divided into three types: mineral oil, semi-synthetic oil, and fully synthetic oil. Mineral oil is the most basic and cheapest type of engine oil, generally classified as SJ or below, and is only suitable for low-end cars or some new vehicles. Functions of engine oil: Lubrication to reduce wear: There is rapid relative sliding between the piston and cylinder of the engine, as well as between the main shaft and bearing bush, which can easily cause wear. High-quality engine oil can form a sufficiently thick oil film between the two sliding surfaces, separating the relatively sliding parts to reduce wear. Cooling and temperature reduction: Engine oil can carry heat back to the oil tank and then dissipate it into the air, helping the radiator cool the engine.
Even if the car is not driven frequently, I believe it's necessary to change the oil at least once a year. When driving less, many car owners tend to overlook regular maintenance, but engine oil gradually deteriorates over time, absorbing moisture and impurities from the air, which reduces its lubricating effectiveness. I remember one year when I was on a business trip and my car was mostly parked in the garage without moving. By the end of the year during a check-up, I found the oil had degraded, nearly affecting the engine's performance. Experts generally recommend following the "time or mileage, whichever comes first" principle—for example, changing the oil every six months to a year or after reaching 5,000 to 10,000 kilometers. However, if you drive less, focusing on the time interval is safer. Don’t rely solely on dashboard reminders; you can occasionally pop the hood to check the oil’s color and viscosity. If it appears black or thin, it’s time for an early change. Developing this habit can extend the engine’s lifespan and avoid costly repairs. In short, don’t delay too long—a simple annual oil change keeps things worry-free.
