Oil has no shelf life. The composition of petroleum is very complex, composed of a large number of alkenes, alkynes, hydrocarbons, and alkanes. Its composition is not constant. The underground oil has existed for hundreds of millions of years, and its composition is changing. However, humans make refined oil by separating various chemicals , even if the composition changes, so there is no expiration problem.
But if oil is stored in the open air for a long time, its composition will undergo some unpredictable and irreversible changes, resulting in the loss of valuable substances in the oil itself.
While oil has no shelf life, finished gasoline and diesel do. If stored for a long time, the composition of gasoline and diesel will change, and most of them can still be used. However, for the engine, this can cause some problems. The shelf life of different types of refined oil is different, and the storage environment will also affect the preservation state of refined oil. It is also possible to render them unusable if they are left in poor condition for a long time.