
Engine oil does expire. Since engine oil is formulated by adding various chemical additives to a base oil, these chemical additives have their own shelf life. Therefore, selecting the right oil quality and adhering to the recommended oil change intervals are crucial. Once opened, engine oil has a shelf life of 6 to 9 months. Relevant details are as follows: 1. Engine oil is highly sensitive to moisture in the air, ambient temperature, and light exposure. Prolonged exposure to air or strong light can cause it to degrade. 2. Using engine oil past its shelf life can cause significant damage to the car's engine, such as reduced lubrication effectiveness and compromised cooling performance. 3. Engine oil, also known as motor lubricant, serves multiple functions including lubrication, cleaning, cooling, sealing, wear reduction, rust prevention, and corrosion protection for the engine.


