What to Know About Recycling Oil

Medically Reviewed by Dany Paul Baby, MD on January 17, 2023
5 min read

Performing your own car maintenance is a satisfying and impressive talent. Changing your car’s oil is a standard do-it-yourself task, but many people don’t know the importance of recycling oil. 

The basic recipe for motor oil is a base oil plus additives. Synthetic motor oil has chemically modified components to make it cleaner and more efficient.

What is base oil? Base oil is a refined crude oil. Crude oil is the hydrocarbon mixture that’s pulled from the ground.

What additives are in motor oil? Motor oil lubricates your engine’s parts so that the engine runs. Additives in motor oil help the motor oil do certain jobs better.

For example, motor oil helps keep the engine’s parts clean. Modern motor oils may have detergent added to improve the oil’s ability to remove and suspend dirt in the oil.

Motor oil will be around 70% to 90% base oil, while the rest is additives. The additives in your motor oil will depend on the brand and goal of the motor oil.

What happens to motor oil? Motor oil is persistent and degrades slowly. It doesn’t wear out, but it gets contaminated with dirt, moisture, and other chemicals.

The oil stops doing its job efficiently once the oil is too dirty. That’s why you need an oil change.

If you change your oil at home, don’t toss the used oil in the trash or pour it out somewhere. Improper disposal of used motor oil can cause detrimental damage to the environment.

Water contamination. Motor oil can contaminate water supplies. A gallon of motor oil (about the amount left over from an oil change) can contaminate 1 million gallons of water.

Danger to animals. Contaminated water can harm animal populations. Oil is viscous and can stick to the fins, feathers, and hair of an animal.

A contaminated source of water can cause animals to move. Animals moving to other areas can cause damage to ecosystems. 

Why is motor oil dangerous? Insolubility, persistence, and slow degradation is a recipe for a dangerous material. These features mean that motor oil can contaminate water for a long time.

The additives in modern motor oil can exacerbate the oil’s toxicity in the environment.

Most people know about recycling plastic bottles and tin cans, but recycling motor oil is one of the best forms of recycling. Motor oil never gets old, only dirty, so it’s a perfect candidate for recycling. 

It’s not only your car’s oil! You can recycle oil from all sorts of vehicles, like boats and lawnmowers.

You can also recycle other vehicle fluids, like hydraulic oil, transmission fluid, and antifreeze. If you’re performing a lot of car maintenance, keep the chemicals separate for recycling or safe disposal. 

Motor oil recycling process. You can’t recycle oil yourself. It needs to go to a special facility that recycles the oil. 

Since the oil is dirty, the recycling process is a complex way of removing the contaminants. The primary method of recycling motor oil is called vacuum distillation.

The oil is boiled in a powerful vacuum to separate the oil molecules from everything else. The process is similar to distilling alcohol to make spirits.

Hydrotreating or solvent extraction processes follow vacuum distillation. These follow-up processes remove trace contaminants that weren’t removed through distillation. 

What is recycled oil used for? The oil after recycling is a re-refined base oil that’s as good as refined oil. The recyclers sell it back to companies to mix with additives for use as motor oil.

Used oil may be used to power large machinery instead of being recycled. It can be burned by industrial boilers for fuel at power plants or other industrial sites.

Benefits of recycling motor oil. Recycling motor oil keeps it out of the environment. Producing re-refined oil takes less energy than refining crude oil, so it’s better for the environment.

Crude oil comes from plant and animal remains from millions of years ago. It’s a finite resource that can last longer with oil recycling.  

Re-refined oil is as good as refined oil. It must meet the same standards as refined oil and doesn’t change the performance of the vehicle.

If you’re changing your car’s oil at home, you’ll need to send the oil off for recycling. 

Store in a clean container. Pour the old oil into a container using a funnel so none of it pours onto the ground. The container should be clean and have a tight lid like an empty water jug.

Avoid containers that once held chemical cleaners or other car fluids. They can contaminate the oil and make it harder to recycle. 

If you’re an avid do-it-yourself car technician, you may end up with a lot of used car fluids, like brake fluid. Don’t mix them with the oil, or it can’t be recycled.

Recycle the filter. The oil filter can be hazardous like motor oil, so you’ll need to take it to recycling with your used oil. Drain the oil from the filter and set it aside for recycling.

Once you have your oil in a container, oil filter drained, and car up and running, you’ll need to have your oil recycled. 

Recycle your oil. You have a few options to recycle your oil that you’ll need to research. Your local service stations and mechanics may collect used oil and filter.

You can contact your local trash and waste collectors. Some of them may accept used oil, which you might be able to leave on the curb for pickup.

Lastly, check with your local government agencies in charge of waste management. They can inform you on where to take your used oil for recycling.

Many people who change their car’s oil don’t realize that motor oil needs to be recycled. Luckily, there are many systems in place to make sure you can recycle your oil and keep it out of the environment.