Can semi-synthetic oil still be used after being stored for a year?
2 Answers
Semi-synthetic oil cannot be used after being stored for a year. Semi-synthetic oil is generally replaced every 7,500 kilometers or approximately 7 months. The replacement steps are as follows: 1. Lift the vehicle, remove the protective plate, and place a container under the oil drain plug; 2. Unscrew the oil drain plug, use an air gun to blow for two minutes at the oil filler port, tighten the oil drain plug after draining, and wipe it with a tissue to check for oil leaks; 3. Reinstall the protective plate, lower the vehicle, and use a funnel to add oil at the oil filler port. The functions of engine oil are: 1. To allow sliding between the piston and cylinder, and between the main shaft and bearing bush, preventing wear on parts; 2. To assist in cooling and temperature reduction; 3. To clean carbon deposits and sludge from engine parts; 4. To seal and prevent leaks; 5. To prevent rust and corrosion; 6. To dampen and cushion vibrations; 7. To resist wear.
Every time I change my oil, there's some leftover semi-synthetic oil. If it hasn't been opened, it's usually still usable after storing for a year. Oil bottles typically have production dates and expiration dates marked, mostly 3-5 years, so one year is relatively short. As long as it's stored in a cool, dry place away from moisture or direct sunlight, it should be fine. Last time, my oil was stored for 14 months, and when I opened it, the color was normal with no strange odor. I poured it directly into my car and used it for several months without any issues. However, if the oil has been opened and stored for a year, you really need to be careful. Exposure to air can cause the oil to oxidize and deteriorate, potentially leading to engine seizure or increased noise. So, only sealed or unopened oil can be saved for later use. It's a good habit to regularly check the dates on oil bottles—don't save a little money only to end up with bigger problems.
