There are many practical uses for used motor oil. A primary use is to rerefine it into a base stock for lubricating oil. This process is very similar to the refining of crude oil. The result is that the rerefined oil is of as high a quality as a virgin oil product.

A secondary use of the used oil is to burn it for energy. Large industrial boilers can efficiently burn the used oil with minimum pollution. As a result some used oil is sent to power plants or cement kilns to be burned as fuel. On a smaller scale small quantities of used oil are burned in specially designed heaters to provide space heating for small businesses.