Automotive Fleet
MenuMENU
SearchSEARCH

Re-refined Oil: In with the Old, Out with the New

Due to recent improvements in re-refining technologies, re-refined oil is now certified by the American Petroleum Institute and recognized as comparable to virgin oil by leading vehicle manufacturers in the industry.

by Brittni Rubin
October 26, 2011
5 min to read


In the past, fleet managers didn’t allow use of re-refined oil in their maintenance operations based on concerns about product quality. A study funded by the California Integrated Waste Management Board in 2006 found that the majority of fleet managers surveyed held that opinion.

However, as re-refining technology continues advancing, and the push toward buying re-refined oils is stronger than ever, it is time to revisit the matter and ask: what exactly is re-refined oil, how has it changed, and should fleets make the switch?

Ad Loading...

What is re-refined oil?

Re-refined oil is used motor oil that gets cycled through a refining and blending process twice.
Oil does not break down, it simply gets dirty. Additives become depleted, and the chemicals that make up those additives break down. The re-refining process restores the damaged product by cleaning up the used oil and adding new additives.

After a technician drains used oil from a vehicle’s crankcase and sends it to a refiner, the oil goes through a chemical pretreatment, followed by a distillation process that removes all of the contaminants in the oil. The refiner then hydro-finishes the oil, a procedure that eradicates any remaining impurities. Lastly, the refiner puts it into a blender that combines the re-refined oil with a fresh additive package. 

The finished product is an American Petroleum Institute (API) approved Group II base oil equivalent to most virgin motor oils currently on the market.

“You have to meet a certain specification to get the API seal on your material, and recycled materials don’t get any special waivers,” said John Wesley, CEO of Universal Lubricants, a closed-loop provider that collects spent motor oil in their own trucks, re-refines it, and then sells it back to the marketplace. “We have to meet those same high criteria that a virgin produced product does.”

Technological Advances

Many state and local agencies, in addition to private companies and even the Federal government, have already switched over to re-refined oil for their respective vehicle fleets. Universal Lubricants regularly provides their product to the FBI and U.S. Border Control. 

Ad Loading...

Although re-refined oil has been around for longer than one would think, there has recently been stronger interest in using it. Why the sudden shift?    

With the standards for technology that exist today, the ability to process an API-quality product has become more than accessible.

In the original days of oil re-refining, dirty oils were run through a sock. This removed some heavy particles; however, it did not create a product usable in vehicles. Companies then tried moving to acid-based clay technology, which produced usable but subpar oil.

Finally, with the advent of new technologies that have hydro-treating capabilities — such as high heat and pressure, and the ability to introduce hydrogen into oil — companies were finally able to create a product comparable to virgin-produced base oils. Over time, refineries were able to polish the molecular structure of re-refined oil to create a higher-quality finished product as well.

“I’d say you’re able to create a better product than virgin because you’re starting with a better product on the front end,” said Wesley. “Crude oil by its very nature is extremely nasty — only two percent of a barrel of crude ultimately winds up as base oil. Re-refined oil skips that starting [stage] with a cleaner initial product.”

Ad Loading...

Now re-refined oil comes in a variety of weights and blends suitable for use in most engines, including those that run on gasoline, diesel, alternative fuels, or hybrid electric systems. Today, with high-quality finished products available as a result of improved technology, it’s a good time make the switch to re-refined oil.

Re-refined Oil’s Financial and Environmental Benefits

Re-refined oil’s green components are fairly obvious—it is recycled, and therefore helps reduce the depletion of natural resources by using less crude oil. It only takes one gallon of used oil to make 2.5 quarts of re-refined oil, whereas it takes 42 gallons of crude oil to make 2.5 quarts of virgin oil.

According to California’s Department of Resources Recycling and Recovery (CalRecycle), re-refined oil only takes about one-third the energy needed to refine crude oil.

Using re-refined oil can also help you save money on maintenance costs for your fleet. It helps improve operating costs on a cent per mile basis, as you can constantly recycle the oil you’re using. If end-users purchased re-refined oil in greater quantities, its use could help reduce the potential for spikes in gas prices and reduce U.S. dependence on costly foreign oil.

Many consumers worry that re-refined motor oil loses some of its lubricating properties when compared with virgin motor oil; however, CalRecycle refuted this concern in its recently issued list of disproven myths. As long as the re-refined oil you are purchasing is API-certified, it is in the same quality as virgin oil.

Ad Loading...

In fact, major automakers, such as Ford, GM, Mercedes Benz-and others have conducted their own testing. Each company went on record stating that the use of re-refined motor oil is not only a viable option, but it also in no way infringes upon manufacturers’ warranties on their engines.

“Using re-refined oils for a fleet is completely safe and the most environmentally sustainable thing you can do besides getting on horseback,” said Wesley. “The advantage is that you can get a product that keeps your fleet on the road, a product that will meet the standard warranties and extended warranties placed on your vehicles, and you can do something good for the environment all for a price equal to — if not less than — what you’re currently paying.”

Subscribe to Our Newsletter

More Green Fleet

Sketch of chassis cab truck.
Green Fleetby Chris BrownMarch 9, 2026

Startup ZMD Motors Developing Electric Conversion for Ram 5500 Work Trucks

Detroit-based company says it has begun early development of a system to convert internal combustion Ram 5500 chassis-cab trucks to electric power.

Read More →
SponsoredFebruary 26, 2026

MOVING ON FROM DEBATE: A Guide for Fleet Managers Who Just Want To Get Electrification Done

Fleet managers are done with the debate—and focused on execution. Learn how to build a practical electrification strategy that aligns infrastructure, operations, and financing while keeping costs controlled and deployment scalable with support from Blink Charging. Discover how smart planning today positions fleets for long-term performance and ROI.

Read More →
EV charging symbol
Green Fleetby Chris BrownFebruary 12, 2026

U.S. EV Adoption Is Climbing, but Commercial and Passenger Markets Diverge

New industry group data revealed that light-duty electric vehicle sales are hitting record market share and volumes, while commercial EV volume dipped. What’s driving the fluctuations?

Read More →
Ad Loading...
SponsoredFebruary 6, 2026

Hybrids: Electrification Without the Challenges

For fleet managers, fuel is one of the biggest line items in the budget — and it's one hybrids can shrink without changing how your people work. Download the eBook to see the numbers, understand the technology, and get a step-by-step guide to making the switch.

Read More →
A side view of the yellow, blue, and red Slate Auto electric pick-up truck and SUV
Upfittingby Martin RomjueDecember 8, 2025

How To Upfit Electric Work Trucks and Vans

The biggest challenge lies in balancing additional equipment and accessories with EV battery capacity and range.

Read More →
Green Fleetby Martin RomjueDecember 4, 2025

How Fleets Can Adjust Approaches To EV Adoption

With the expiration of federal incentives, EV success now hinges less on government policy and more on discounts, battery tech progress, increased range, and broader infrastructure.

Read More →
Ad Loading...
Panelists on stage at FFC.
Fleet Forwardby Martin RomjueOctober 29, 2025

Despite World Troubles, Forward Thinking Guides Fleets

Fleet operators shared their challenges during an annual conference that embraced the latest advances across all aspects of running private- and public-sector vehicles.

Read More →
Illustration of GM Energy’s vehicle-to-home system showing an electric truck connected to home power storage, the grid, and GM Energy Cloud through the myOwner app.
Green Fleetby News/Media ReleaseOctober 28, 2025

GM Energy Details Partnerships and Targets for Public Charging Build-Out

EVgo, Pilot, ChargePoint and IONNA named; goal is 35k GM-invested DC stalls by 2030, with customer-experience upgrades at sites.

Read More →
Chart showing September 2025 EV sales. New EV sales totaled 147,716 units, up 44% year over year, and used EV sales hit 40,569 units, up 76%, marking strong third-quarter performance.
Green Fleetby News/Media ReleaseOctober 23, 2025

Q3 Electric Vehicles Sales Hit Record High

EV buyers took advantage of the final federal tax credit days, while average prices edged up for new EVs and continued to decline for used models.

Read More →
Ad Loading...
A green vertical bar graph chart showing the rises and dips in quarterly EV sales since early 2022.
Green Fleetby News/Media ReleaseOctober 10, 2025

EV Sales Hit Record in Q3 Before Incentives Expire

But most OEMs record low-volume sales, which means EV profitability remains a distant dream for nearly every automaker.

Read More →