Used oil is exactly what its name implies: any petroleum-based or synthetic oil that has been used. Oil keeps our cars, motors, and many other machines running smoothly. Recycling and reusing used oil is preferable to disposal and can provide great environmental benefits. Recycled used motor oil can be re-refined into new oil, processed into fuel oils, and used as raw materials for the petroleum industry.Used oil can be re-refined into lubricants, processed into fuel oils, and used as raw materials for the refining and petrochemical industries. Additionally, used oil filters contain reusable scrap metal, which steel producers can reuse as scrap feed.