Frequently Asked Questions

Everything You Need to Know.

Why not burn waste lube oil as fuel?

Annually in New Zealand, millions of litres of waste lubricating oil are incinerated for fuel, a practice once broadly classified as "recycling." However, this definition is inconsistent; the burning of paper, organic, or chemical waste isn’t considered recycling, and oil should be no exception.

Burning waste oil may appear cost-effective, but this comes at a high environmental cost. It is destroying a finite, valuable resource and releasing harmful emissions into the atmosphere.

For every tonne of oil burned, approximately 2.92 tonnes of CO₂ equivalent are emitted. Used oil also contains hazardous compounds including polyaromatic hydrocarbons, heavy metals, and dioxins many of which are carcinogens. When burned improperly, these substances can be released into the environment.

Can waste oil be reused as lubricating oil?

Yes. Up to 70% of waste oil is good lubricating oil and Glide can recover as much as 99% of this. Lubricating oil does not wear out, it simply becomes contaminated with use. Re-refining recovers the good oil with no loss in quality.

Recovering 99% of the good base oil enables near-indefinite reuse. This makes lubricating oil a circular resource that can be reclaimed and reused repeatedly.

What are the environmental benefits of re-refining waste lube oil?

Re-refining contaminated lubricating oil offers significant environmental benefits compared to burning or producing virgin base oil from crude. Notably:

  • Uses less than half of the carbon compared to making base-oil from crude.*
  • Reduces pollution from toxic compounds found in used oil
  • Supports circular economy principles, giving oil a second life
  • Eliminates secondary waste, with up to 99% recovery of the base oil as well as the recovery of the other compounds within waste oil (including light end fuels and bitumen residue) that can also be reused.
  • Re-refining is currently the most environmentally responsible solution for managing used oil.

*Independently verified by Toitū Envirocare

Who is GLIDE?

GLIDE is a New Zealand-owned company, operating the country's only facility for re-refining waste lubricating oil.

Glide specialises in both the collection and re-refining of waste oil. Its closed-loop process generates no secondary waste and delivers a significantly lower carbon footprint compared to crude-derived base oils.

Glide pairs its world-class re-refining capability in Pukekohe with a nationwide collection network, offering an efficient, end-to-end recycling service for waste oil producers including transport fleets, heavy machinery operators, mining companies, and local councils.

How does GLIDE help organisations meet their Extended Producer Responsibility (EPR) obligations?

GLIDE enables oil producers, fleet operators, and service providers to meet their EPR responsibilities by offering efficient, transparent, and traceable collection and recycling services.

Through re-refining, GLIDE ensures used oil is handled at the highest level of the waste hierarchy, aligning with best-practice environmental management and corporate ESG commitments.

What is the GLIDE RRBO?

GLIDE Re-refined Base Oil (GLIDE RRBO) is our premium lubricant base oil produced through our advanced re-refining of waste oil. Using state-of-the-art processing technology, we transform used lubricants into high-quality base oil that meets or exceeds industry specifications. GLIDE RRBO offers the same performance characteristics as virgin base oils while supporting environmental sustainability by giving waste oil a second life.

What does waste oil consist of?

Lubricating oils become contaminated during service and are then referred to as “Waste Oil”. Waste Oil is a bit misleading as you would think that it has no value, however the largest component is good quality Base Oil which is still chemically intact, this generally makes up around 70% of the total volume of waste oil collected. Glide can recover as much as 99% of this oil and make it new again.

The other components in the Waste oil are:

  • Water - This is removed through the re-refining process and is either treated and goes to trade waste, or is evaporated off in the process.
  • Light Cut & Middle Distillate - In the combustion chamber of engines, some of the fuel source can end up in the sump with the lubricants. This generally occurs from a process known as "Blowback". Glide separates these products (generally petrol and diesel) so they can be reused.
  • Asphalt Extender - This thick tar like substance is what comes off the bottom of the re-refining process and captures everything which is left behind. The Asphalt Extender can contain such things as thermally degraded oil, additive breakdown components and wear products. The good news is that this too can be reused - typically being used as an asphalt extender in roading, for construction materials or as fuel blend.

What has happened to New Zealand’s waste lube oil in the past?

Historically, waste lubricating oil in New Zealand has been predominantly burned as a low-cost industrial fuel, a practice that discards its true value and contributes to unnecessary emissions.

Re-refining used oil back into base oil currently represents the highest standard of waste oil management, delivering both environmental and economic benefits by maximising its reuse within New Zealand.



What are the economic benefits of re-refining waste lube oil?

Rather than burning waste oil and losing its value entirely, GLIDE regenerates it into high-quality base oil, creating a more circular resource.

This maximises the economic potential of a locally available material and contributes positively to New Zealand’s economy.

By turning waste into a valuable input for domestic and global markets, GLIDE demonstrates how smart, sustainable innovation can drive both environmental and economic gains.

How does re-refining reduce emissions compared to other disposal methods?

To make 1 litre of Base Oil, it takes around 42 litres of crude oil. Re-refining requires significantly less energy than producing base oil from crude, and avoids the emissions released during combustion.

For every tonne of oil re-refined instead of burned, nearly 3 tonnes of CO₂ equivalent emissions are avoided*.

*Independently verified by Toitū Envirocare

Is re-refining more expensive than burning waste oil?

While burning waste oil may offer short-term financial savings, it externalises environmental costs and permanently destroys the resource.

Re-refining is a long-term investment in sustainability that, when accounting for avoided emissions, regulatory risk, and resource value, is a more cost-effective and responsible solution overall.

GLIDE also offers efficient waste oil collection to waste producers, helping remove barriers to participation.

What are lube oils?

Lubricating oils are fluids composed of base oils blended with performance-enhancing additives. Their primary functions are to reduce friction, dissipate heat, and suspend impurities, ensuring the smooth and efficient operation of engines and machinery.

Is your carbon savings data independently verified?

Yes, our carbon saving estimates are all independently verified by Toitū Envirocare — one of New Zealand's most trusted independent certification organisations for reducing greenhouse gas emissions.

To find out more on our Toitū verified methodology, please get in touch for the full LCA.

Who is WPC?

WPC (Waste Petroleum Combustion Ltd) is the same company you’ve always known - now trading as Glide. We rebranded in late 2025 to better reflect what we do today. Nothing else has changed: same ownership, same friendly team, same reliable service. The new name simply aligns with our evolution from traditional waste-oil collection into a more innovative, circular, and environmentally focused re-refining operation. All current accounts, contracts, and services remain exactly as they were - just with a new name and look that represent where we’re heading.