While cleaning out your garage or storage space, you may come across an old bottle of motor oil and wonder if it can still be used. Knowing how to tell usable oil from spoiled fuel will help you avoid potentially damaging your engine. Here's a closer look at how to tell if your old oil can still be used and whether it’s gone bad in your engine so that you can get an oil change before you require costly auto repairs.

Can Motor Oil Expire?

Unlike gasoline, which can begin to destabilize in as little as three months, motor oil can last for extended periods if kept in a sealed container away from extreme temperatures. However, both substances can degrade, as lighter petroleum hydrocarbons evaporate over time. If exposed to the ultraviolet (UV) rays in sunlight, petroleum products will oxidize, leading to a thicker consistency and an increase in deposits of sludge and varnish.

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The shelf life of motor oil varies, depending on its composition and manufacturers’ recommendations. Some products may last for as little as two years, while others can last up to five years. Opened containers of oil may have a reduced shelf life due to the oxygen present inside.

How to Tell if Your Car Needs an Oil Change

Oil can also expire while in your engine due to heat, friction, soiling, and exposure to air. For example, oil naturally collects traces of dirt, corrosion, and metal as it circulates through your engine. Over time, these substances will increase the oil’s viscosity and reduce its ability to lubricate moving parts. Heat will also thicken oil since it leads to evaporation of lighter ingredients.

Other issues such as leaks, water getting into your oil, and a damaged cooling system can result in spoilage. Schedule an appointment at an auto repair shop if you notice signs like excessive exhaust, unusual engine noises, a lit check engine light, or shaking while idling your engine.


When you’re due for an oil change, the team at Alliance Collision in Rochester, NY, will provide quick service and your choice of premium lubricants. Having served drivers since 1946, the experts at this auto repair and roadside assistance shop can help with everything from routine maintenance to collision repair and tire services. Call (585) 232-2390 to schedule an oil change, or visit them online for more information on their services.