Can engine oil still be used after being opened for one year?
2 Answers
It is best not to use engine oil that has been opened for one year. Once opened, the oil is exposed to air and comes into contact with water molecules and oxygen, which degrades its quality and shortens its service life. Here are some precautions for using engine oil: 1. The storage environment for engine oil must be dry and free from sunlight. If not in use, try to keep it unopened to prevent oxidation. If the oil has been opened, you can seal the bottle opening with a layer of plastic wrap and tighten the cap. 2. Never use expired engine oil. Using expired oil can cause significant damage to internal engine components. Even if expired oil retains some lubricating properties, it cannot maintain its original effectiveness and fails to meet the engine's operational requirements.
As an experienced DIY oil changer, I must remind you that motor oil opened for over a year should not be used. Once exposed to air, engine oil gradually oxidizes and deteriorates, losing its original lubrication and protection capabilities. I've used aged oil several times before, which resulted in increased engine noise and even premature wear problems. The additives in motor oil degrade upon air exposure, and moisture absorption makes it thinner or causes sedimentation, significantly reducing cleaning and cooling effectiveness. If you insist on using it, you might save a few dozen dollars, but engine overhaul costs could run into thousands. My advice: always store oil in sealed containers in cool places, and use opened oil within six months. Regular oil changes are the wisest choice - keeping your car running smoothly while avoiding unnecessary troubles. Honestly, safety first is what matters most!
