Used motor oil is both a hazardous waste and valuable resource

According to the National Highway Traffic and Safety Administration (NHTSA), there are over 248 million passenger cars and light trucks on U.S. roads. If each engine holds an average of 5 quarts of oil and has its oil changed twice a year, that generates 620 million gallons of waste oil per year. That’s 57 times the quantity that spilled from the Exxon Valdez tanker in 1989.

Have you ever wondered what happens to all that oil?

Used motor oil is a valuable resource. The American Petroleum Institute (API) defines two uses for the stuff: it can be re-refined into lubricating oil, or it can be burned for energy. With processes similar to refining crude oil, used motor oil can be re-refined into base stock for other lubricants, and that stock is almost as high a quality as virgin oil. The process also requires 50 to 85% less energy than refining crude oil. In the past, re-refined motor oil was commonly available as motor oil, but today’s engines require highly engineered lubricants that rely heavily on additives to meet very specific performance standards. Often it costs more to use re-refined oil as base stock for that kind of motor oil. It can be done, but today re-refined oil is more commonly used to make industrial lubricants rather than motor oil.

It’s even more commonly used as heating oil. Because it requires almost no processing, used motor oil is typically burned in power plants and large industrial furnaces, such as cement kilns. Because it burns so clean, it’s also suitable for smaller applications like shop heaters, which typically require nothing more than a filter to prepare the oil for burning.

Almost all of this valuable resource is collected from fleet garages and commercial automotive service shops, but Castrol USA, a division of BP Lubricants, says about half the oil changes performed in the U.S. each year are done by car owners themselves. Unfortunately, many don’t know what to do with their drain oil, and they often end up disposing of it improperly. According to the U.S. EPA, the oil from one oil change is enough to contaminate one million gallons of fresh water. “We have a responsibility to help protect the environment,” said Matt McHale, Associate Brand Manager at Castrol USA. Therefore, the company has launched a campaign to inform customers about proper methods of recycling used motor oil. They have identified over 30,000 locations in the U.S. that accept used motor oil for recycling, and these include auto parts stores and service shops.

Recyclers who collect used motor oil form stores and shops either process that oil themselves for use as heating fuel, or they resell it to an oil refinery. Perhaps this why they’re so much variability in who pays to empty the used-oil tank. All the shops contacted for this report stated that at times they must pay to have the old oil hauled away, and other times the recycler buys it from them. “It goes back and forth,” said Mike Toth of Paoli Auto Repair. “We used to pay [for removal], but now they’re buying the oil from us.” They expect to pay for removal again in the future, but not forever.

As crude oil prices continue to rise, used motor oil becomes more valuable. It’s even been suggested that consumers may one day be able to redeem old oil for cash or credit at their parts store. Meanwhile, Castrol’s website (www.castrol.com, search word “recycle”) and the API website (www.recycleoil.org) both offer consumer information on how to recycle used motor oil. Castrol’s McHale offered these additional tips: “Follow state and federal regulations, keep good records, and keep the used oil separate from everything else.”