Can engine oil still be used after its expiration date?

[VanCharles]

Engine oil cannot be used after its expiration date. The oil absorbs moisture, undergoes chemical and physical changes, which reduce its lubrication, cooling, sealing, and anti-corrosion properties. Additionally, degraded oil can produce impurities that clog oil passages. If you have a large quantity of oil and don't want to waste it, you can perform an oil test before use. Professional testing equipment can quantitatively and accurately assess the quality of the oil. Engine oil serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption for the engine. It consists of two main components: base oil and additives. The base oil is the primary component of lubricating oil, determining its fundamental properties, while additives compensate for and improve any deficiencies in the base oil's performance, imparting new characteristics, making them a crucial part of the lubricating oil.