What is the shelf life of opened engine oil?

[JohnAnn]

The shelf life of opened engine oil is approximately one year. The method for changing engine oil is as follows: 1. Use a jack to lift the vehicle, locate the oil drain bolt and loosen it to drain the oil; 2. After removing the oil filter, place a container beneath it; 3. Install a new oil filter and add fresh engine oil. Engine oil, also known as engine lubricant, is composed of base oil and additives. The base oil is the main component of the lubricant, determining its fundamental properties, while additives compensate for and improve any deficiencies in the base oil's performance. The functions of engine oil include: lubricating and reducing friction in the engine, assisting in cooling, sealing to prevent leaks, preventing rust and corrosion, and providing shock absorption.