Can 5-year-old engine oil be used?
2 Answers
Unopened engine oil can be stored for 5 years, but opened engine oil can only be stored for 12 months. It is not recommended to use expired engine oil. The national standard for engine oil shelf life is 5 years, with some types lasting up to 12 years. Generally, engine oil within 3 years should be fine. Engine oil is not a food or pharmaceutical product, so the General Administration of Quality Supervision does not require products with a shelf life exceeding certain years to indicate an expiration date, which is why engine oil does not have a marked shelf life. Additionally, fully synthetic oil has a longer shelf life than mineral oil. To maintain the performance of lubricating oil, it is generally recommended to store it in a cool, dry place to prevent contamination by water or other impurities.
I think it's best not to use engine oil that has been stored for 5 years, as oil deteriorates over time and its lubricating effectiveness diminishes significantly. When I was younger, I also stored engine oil, but later discovered that after more than three years, it may oxidize or absorb impurities. Using such oil can accelerate engine wear, and even lead to oil seal leaks or oil burning issues. If the storage environment is poor, such as in a hot garage or damp place, the oil deteriorates even faster. Rather than saving a little money this way, it's more reliable to change to fresh oil regularly and check its condition every 5,000 kilometers or every six months. Remember to choose reputable brands; for example, full synthetic oils have a slightly longer shelf life, but don't delay too long—safe driving is more important.
