
It is acceptable to change fully synthetic motor oil once a year. Fully synthetic motor oil appears as a clear, semi-transparent or transparent liquid with a shelf life of up to 5 years. Synthetic motor oil is chemically engineered lubricant whose composition can be adjusted according to different usage purposes. The replacement procedure for fully synthetic motor oil is as follows: 1. Start the vehicle engine for preheating; 2. Unscrew the drain plug; 3. Remove the oil filter; 4. Apply new oil to the gasket of the new filter; 5. Pour new oil into the oil pan; 6. Check for leaks at the lower part of the engine and verify oil level with dipstick before starting the engine for testing.

When it comes to changing full synthetic oil once a year, I think it really depends on how you drive. I have extensive experience with cars and have driven under various conditions. Generally, full synthetic oil has better durability, and manufacturers usually recommend changing it once a year or around 10,000 kilometers. But if you drive a lot, like daily highway or long-distance trips, you might need to change it sooner. On the other hand, if the car sits idle, the oil will slowly oxidize, and even if a year passes, it’s usually not a big issue. The key is to regularly check the dipstick—if the color darkens or there are impurities, don’t delay. After all, engine repairs are expensive, while an oil change is cheap and hassle-free. My neighbor has a car that’s rarely driven and changes the oil once a year without any issues; meanwhile, my colleague drives aggressively and needs to change it every six months. In short, following the manufacturer’s manual while adjusting flexibly is the way to go—it saves you trouble.

I suggest you really take a look at the owner's manual—it's all clearly written there. Full synthetic oil is of better quality, with higher temperature resistance and oxidation stability, theoretically allowing most cars to go a year between changes. When I ran an auto repair shop, I often dealt with such inquiries—too many people just focus on time without checking actual conditions. For example, if your car frequently takes short city trips, the engine accumulates more dust, and the oil degrades faster, possibly requiring an earlier change. If you only drive a few thousand miles a year and park in an underground garage, the oil may remain in good condition. But don't rely solely on time—consider mileage and driving conditions. Regularly checking oil consumption is necessary; if it thins out or develops a burnt smell, address it immediately. Safe driving is key—don't risk major issues over minor savings. Annual maintenance is generally fine, but don't slack on it.

I don't drive my car much, with a short commute distance and only taking the family out on weekends without going far. Changing full synthetic oil costs a bit, but I'm used to doing it once a year for convenience. Research shows this type of oil has stable performance and a long shelf life—with infrequent driving, you could even stretch it to two years. But you need to watch the parking environment; damp garages can cause the oil to absorb moisture and degrade. I check the dipstick monthly and only stick to annual changes if the oil still looks clear. Of course, frequent drivers shouldn't follow my lead—change when needed to prevent risks. Saving money and time is quite a good deal.


