Can fully synthetic engine oil be changed once a year?
2 Answers
Fully synthetic engine oil can be changed once a year. Synthetic engine oil is chemically synthesized and manufactured, with its various components adjusted according to different usage purposes. The reason engine oil needs regular replacement is that its performance degrades over time, making it unable to meet the engine's requirements. Engine oil, as a lubricant, plays crucial roles in the engine, including lubrication, cleaning, cooling, sealing, reducing wear, damping vibrations, and preventing rust and corrosion. Currently, there are three types of engine oil on the market: conventional mineral oil, semi-synthetic oil, and fully synthetic oil.
I've been using full synthetic oil for many years, and I feel that changing it once a year depends on your driving habits and vehicle conditions. Although full synthetic oil has good durability, over time it absorbs moisture and oxidizes, affecting its lubrication performance. I mostly drive short distances in the city, and each engine start puts a burden on the oil, potentially accelerating its degradation within a year. If you drive fewer long distances, have good weather conditions, and low mileage—say, less than 5,000 kilometers a year—you might consider trying it. But don’t forget to check the dipstick; if the oil appears dark or thin, it’s time to change it. Vehicle manuals usually recommend changing oil every 5,000 to 10,000 kilometers, and combining time and mileage is safer. I pay extra attention to the oil condition during cold starts in winter to avoid engine wear. Overall, don’t just focus on time—adjust based on usage to prevent small issues from turning into major problems and save on repair costs.
