Can You Recycle Used Motor Oil?

Used motor oil can be ‘re-refined’ and used again.

Engine oil drain unit. Car on a lift in a car service.
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Used motor oil can and should be recycled. It poses significant health and environmental risks if discarded improperly, and it offers a more efficient, less carbon-intensive alternative to making new motor oil from scratch.

What Is Motor Oil?

Motor oil is any oil used as an engine lubricant. It typically includes gasoline- and diesel-engine crankcase oils, as well as piston-engine oils for cars, trucks, boats, airplanes, locomotives, and heavy equipment, according to the U.S. Environmental Protection Agency (EPA). Motor oils may be petroleum-based or synthetic, although synthetic oils are still primarily made from fossil fuel sources.

Motor oil itself is highly durable, but its dirty job still takes a toll. During normal use inside your engine, motor oil accumulates impurities ranging from dust and dirt to metal scrapings and various chemicals, eventually impeding its lubrication. On top of its own toxicity, used motor oil may be contaminated with dangerous toxins such as benzene, toluene, ethylbenzene, and xylene, as well as lesser-known contaminants like methyl tert-butyl ether (MTBE), a flammable, skin-irritating gasoline additive.

U.S. consumption of lubricating oil is about 2.47 billion gallons per year, according to the Department of Energy. In 2018, more than 1.37 billion gallons of that total were available for possible collection and reuse. Used motor oil is a significant water pollutant in some places, and as nonpoint source pollution, its environmental effects can be widespread. Used motor oil could be a major source of MTBE in groundwater, for example, the USGS notes. And it doesn’t take much to cause trouble—the used oil from a single oil change can pollute as much as 1 million gallons of water, according to the EPA, or about a year’s supply for 50 people.

Fortunately, it’s not only possible to produce good motor oil via recycling; it may also be more efficient and economical than using newly extracted crude. Just 1 gallon of used oil is needed to produce 2.5 quarts of new, high-quality lubricating oil, according to the EPA, compared with 42 gallons of crude oil required to make the same amount.

How to Recycle Motor Oil

use motor oil
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If you take your car to a mechanic for an oil change, they typically will recycle the old oil for you. If you change your own vehicle’s oil at home, the fate of your used motor oil—along with that of nearby wildlife and water quality—is up to you.

Changing your car’s oil can save time and money, but never dump or improperly discard used motor oil anywhere. Be careful not to spill any as you collect it in an oil drain pan, preferably with a tarp or other plastic sheet underneath to catch any oil that does get away. Some oil drain pans are sealable containers, which makes the job easier. Otherwise, you’ll need to transfer the oil from a drain pain into another sealable, spill-proof plastic container. Close the container tightly, and if you aren’t recycling the oil immediately, store it somewhere away from heat, water, sunlight, kids, and pets.

As with paint recycling, motor oil may not be recyclable if it’s mixed with other liquids, so keep it separate, ideally in a labeled container. Many auto parts stores and service stations accept used motor oil for recycling, sometimes charging a fee. Look up businesses near you, and call before hauling your oil there to make sure they’ll take it. You might also want to ask your local waste management authority about hazardous waste collection events, or if used motor oil can be collected with curbside recycling. If so, find out the packaging requirements for used oil collection; don’t just toss it in the recycling bin.

Once it’s collected, used motor oil is sent to processors and refiners, which remove contaminants like water, insolubles, dirt, heavy metals, nitrogen, and chlorine. This “re-refined” oil can then return to service, where it must meet the same refining and performance standards as virgin oil for use in internal combustion engines. While motor oil can be repurposed to serve in other roles like heating fuel, it retains its lubrication properties regardless of how often it’s recycled.

“Extensive laboratory testing and field studies conclude that re-refined oil is equivalent to virgin oil—it passes all prescribed tests and, in some situations, even outperforms virgin oil,” according to the EPA.

Oil Filters Can Be Recycled, Too

Don’t forget about your oil filter. Lots of unsavory debris builds up in there, and it too should be dealt with responsibly. Don’t just throw away used oil filters with household garbage. A filter can be drained by puncturing the dome end with a screwdriver or the claw of a hammer, then resting it on the used oil container to drain, which may take 24 hours. The filter will drain faster if it’s warm.

Once the filter is drained, you might be able to recycle it along with the oil itself. When you call a business, recycling center, or waste management authority to ask if they accept used motor oil, ask about oil filters, too.

How to Dispose of Motor Oil Safely

Due to the toxicity of used motor oil, as well as its high potential for widespread harm as a water pollutant, there aren’t many good ways to dispose of it aside from recycling, which is legally required in some places anyway.

View Article Sources
  1. "Managing, Reusing, and Recycling Used Oil." Environmental Protection Agency.

  2. "Managing Used Oil: Answers to Frequent Questions for Businesses." Environmental Protection Agency.

  3. Baker, Ronald J., et al. "Used Motor Oil as a Source of MTBE, TAME, and BTEX to Ground Water." Groundwater Monitoring and Remediation, vol. 22, no. 4, 2002, pp. 46-51., doi:10.1111/j.1745-6592.2002.tb00770.x

  4. "Used Oil Management and Beneficial Reuse Options to Address Section 1: Energy Savings from Lubricating Oil Public Law 115-345." United States Department of Energy, 2020.

  5. "Used Motor Oil a Potential Source of MTBE in Ground Water." United States Geological Survey.