The importance of recycling used engine oil

First published October 2009, updated January 2012

Many people are aware that old engine oil shouldn’t be dumped, but recycled.Unfortunately, up to 100 million litres (approximately 26.4 million US gallons) ofthe stuff is improperly disposed of each year in Australia alone according toour Department of the Environment, Water, Heritage and the Arts. The globalfigure would be staggering.

It’s dumped in household trash, used as weed killer, pour in ditches, leftlaying about or illegally dumped. Actually, I’m feeling rather guilty as I writethis as I have a gallon or so of old oil stashed away (safely) – still – evenafter over 2 years passing since I first published this article.

Used engine oil is incredibly toxic stuff and a gallon can contaminate onemillion gallons of water. Pouring it on land doesn’t reduce the risk either asit can seep down into the water table as well as rendering the soil incapable ofsustaining plant life.

Used oil doesn’t wear out – it just gets filthy. It can be cleaned ofcontaminants and recycled continuously. It can even be cleaned to the pointwhere it can be reused as engine oil.

The dirty oil goes through the same refining process as oil that is extractedfrom wells, so it’s not exactly a “green” process, but it doesn’t havethe added environmental impact of the extraction. 

New engine oil made from recycled oil meets the standards used in the industrylubrication industry. According to the American Petroleum Institute, re-refinedoil is of as high a quality as a virgin oil product.

The recycling process is as follows:

– Removal of any water
– Filtering to remove solids and additives
– De-asphalting to remove bituminous content
– Distillation

Environmental benefits of recycling used engineoil

Information from the USA Environmental Protection Agency states that re-refiningused oil takes only about one-third the energy of refining crude oil tolubricant quality. It takes 42 gallons of crude oil, but only one gallon of usedoil to produce a half gallon of new, high-quality lubricating oil that can beused in car engines.

While only around 0.9% of crude oil consumption in the USA is in the form ofproducing lubricating oil, when you consider the US chewed through well over 18 million barrelsa day in 2010, it still amounts to a lot. 

Some quick, back of virtual envelope calculations:

18 million x 365 = 6,570,000,000 barrels a year
6,570,000,000 barrels a year x 42 gallons = 275,940,000,000 gallons
0.9% of 275,940,000,000 = 248,3460,000

So, around 248 million gallons of oil is used each year for lubricating engines andmachinery based on the 18 million barrel a day figure.

If all that was recycled, it would mean 124 million gallons, or 2.9 millionbarrels that wouldn’t need to be extracted each year. It’s not an insignificantamount – both in environmental and economic terms.

Other uses for recycled engine oil

While the following uses may not be all that “green”, it goes to showjust how important that this resource is recycled rather than just thrown out.By recycling engine oil, we reduce the need for extraction of crude oil and theassociated environmental impacts of that activity.

– Engine oil can also be used as fuel oil. By recycling just two gallons of usedoil, it has the energy potential to generate enough electricity to run theaverage household for almost 24 hours. One gallon of used oil processed for fuelcontains about 140,000 British Thermal Units (BTUs) of energy. 

– It can be reused as hydraulic oil

– Many petro-chemical based products such as plastics can be made with it

Where to recycle engine oil

To find out where you can recycle engine oil in the USA, try Earth911.organd search for a collection center via zip code.

In Australia, for further information on used oil and to find your nearest usedoil collection facility, contact or call 1800982 006

If you’re in Canada, try the UsedOil Recycling site for information on collection points.

For folks in the UK, visit OilBank Line.

Equally as important as recycling engine oil is to buy products made from thestuff. After learning more about it, I’d have no hesitation in using recycledengine oil it in my car if it was offered as long as it was certified as meeting industrystandards. Perhaps its something to have a chat to our mechanics about.