There is a 4 cents per quart fee on each quart of oil sold in California. The money which is not collected by customers goes into a program which funds oil recycling programs throughout the state of California. Used motor oil can be taken to a special refinery and processed to remove all impurities. The end result is a re-refined high grade oil which can be used as a base stock in the formulation of more motor oil. This base stock is as good as, and sometimes even better than, crude .
Motor oil is truly recyclable.
It can be re-refined again and again. Some of your used motor oil may be going to a re-refinery, but most is not. Most is used as a cheap source of fuel in cement kilns and ships. When this untreated used oil is burned for these purposes, the toxins are emitted into our air. There is not a big market for re-refined oil.