How should opened motor oil be stored?

发布时间：2022年03月14日 14:51

“How long can the remaining half of the oil last if it hasn’t been fully used yet?” After completing a maintenance service, there’s often some oil left over. Typically, friends take this leftover oil home to store themselves and use it again at the next maintenance service. So, how should this half-bucket of oil stored at home be preserved? The causes of oil degradation: Let’s first take a look at what causes engine oil to degrade. The primary reason for oil degradation during storage is its exposure to oxygen, moisture, and impurities in the air. Therefore, once opened, engine oil must be stored in a tightly sealed container. 1. Oxygen: Engine oil consists of base oil and additives. Although base oil is generally quite stable, the heavier components within the oil are more susceptible to oxidation.

　　“There’s still half a bucket of oil left—how long can it be stored?” After completing maintenance, if there’s leftover oil, it’s usually taken home by the team members for safekeeping until the next maintenance service, when they’ll retrieve it again.

　　So, how should the half-bucket of oil you brought home be stored?

　　Causes of Oil Deterioration: Let’s first take a look at the reasons behind oil deterioration. The primary cause of oil degradation during storage is its exposure to oxygen, moisture, and impurities in the air. Therefore, once opened, oil must be stored in a tightly sealed container. 1. Oxygen: Engine oil consists of base oil and additives. While base oils are generally quite stable, the additives—whose role is crucial to the oil’s performance—are much less stable. When exposed to oxygen in the air, these additives readily undergo chemical reactions, especially under sunlight. This leads to the deterioration of additives, significantly reducing the oil’s antioxidant and cleaning properties. 2. Moisture: As the water content increases, some of the oil’s additives become ineffective, resulting in poorer lubrication, reduced viscosity, and an accelerated oxidation process. In mild cases, this can cause premature oil degradation and rusting of engine components; in severe cases, it may lead to serious mechanical failures such as crankshaft seizure or bearing failure. 3. Impurities: Impurities primarily affect the oil’s cleanliness. Once impurities enter the oil, they can impair its lubricating performance and even cause abnormal wear on engine components, thereby compromising the engine’s sealing capability.

　　How to store engine oil:

　　Now that we’ve identified the causes of oil degradation, we can address the problem effectively by finding appropriate solutions. 1. After using the engine oil, immediately tighten the oil cap and cover the barrel opening with a clean plastic film. This will enhance the sealing effect. If possible, you can also seal the barrel lid with wax. 2. Once sealed, store the oil in a dry, cool place, ensuring it’s not exposed to direct sunlight to prevent oil degradation. 3. When you next take out the sealed oil for use, be careful not to pour it all out completely—leave a small amount at the bottom. Generally, oils stored for long periods tend to accumulate trace amounts of moisture at the bottom of the container, which could affect engine performance if added directly.

　　Generally, the storage time after use and sealing will vary depending on the type of motor oil. However, if stored properly, any kind of motor oil can be kept until the next use. Still, we’d like to advise everyone to try to purchase just the right amount of motor oil whenever possible.

Trying to save money can actually lead to big losses—overfilling the engine oil can have serious consequences!

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