The Many Purposes of Used Motor Oil

More than 380 million gallons of used oil are recycled each year, according to the U.S. EPA, that’s more than 50 percent of all motor oil purchased annually.

Longer lasting oils can reduce the generation of used oil. However, once generated, used motor oil can be reused or recycled one of three ways: reconditioning, reprocessing/energy recovery or re-refining. (See diagram below.)


Re-refining used motor oil is typically a sophisticated, multi-stage process that removes impurities so that it can be used as base stock for new lubricating oil.

Fourteen percent of used motor oil is re-refined in the U.S. However, low consumer demand for this product can make re-refining economically unattractive for many oil manufacturers. If you do chose to purchase re-refined motor oil, make sure that the oil specifications for the product meet those required by your vehicle manufacturer.

Used Oil Management Diagram - Click to Enlarge


In some industries, oil is filtered through a commercial filtration system. This process helps remove insoluble impurities so the oil potentially can be used multiple times.

While the cleaning process does not always restore the oil to its original quality, when combined with replenishment of key additives, this process extends the oil’s life and use.

Reuse and Reprocessing

Used lubricants are still petroleum products. When used oil can no longer perform its original lubrication job, it still may be perfectly suitable for reuse as a fuel petroleum product where its energy can be usefully recovered with little or no pre-treatment.

If some treatment is needed before use as fuel, reprocessing of used motor oil removes water and particles, and can even produce an array of fuel products, so that the oil can be burned to generate heat or electricity for commercial operations.

Up to 74 percent of all oil reuse/recycling in the U.S. is for burning in turbines, incinerators, power plants, cement kilns or manufacturing facilities – reducing the need to refine new commercial heating or fuel oil from imported crude oil. An additional 11 percent of used motor oil is burned in specifically designed industrial space heaters.