What is AdBlue? Plus When and How to Refill
AdBlue is an essential fluid for many modern diesel engines, designed to reduce harmful emissions and help your vehicle meet strict environmental standards. While it’s relatively easy to manage, there’s still a bit of confusion around what AdBlue does, how to use it, and what happens if you run out.
We’ve created a quick guide for you, where we’ll walk you through everything you need to know from what AdBlue is and how it works, to where to buy it, how to refill it, and what to do if your vehicle runs dry. Whether you're a DIY type or prefer to leave it to the pros, Brisbane's Downtown Toyota car service department is here to make sure your vehicle stays road-ready and emissions-compliant.
What Is AdBlue?
AdBlue is a special fluid used in many modern diesel vehicles to help reduce pollution. Even though it’s called AdBlue, it’s actually a clear, colourless liquid (not a fuel or fuel additive) and it’s completely safe to handle with care.
It’s made from a mix of purified water and urea (a substance also found in things like fertiliser). AdBlue is stored in its own tank in the vehicle and is part of a system that helps clean up the exhaust fumes coming from the engine.
When a diesel engine runs, it creates harmful gases called nitrogen oxides (NOx), which contribute to air pollution. AdBlue helps break these down into harmless nitrogen (which makes up most of the air we breathe) and water vapour. This process helps diesel vehicles meet strict environmental laws and run cleaner for the planet.
While it's safe to handle at home it’s important that the correct procedure is followed when adding Adblue to your vehicle. If added incorrectly AdBlue can damage your paint and other vehicle components. If you’re unsure or not entirely confident, just like with any other vehicle liquids you can always contact your local service department to top up your AdBlue for you. This can be done during your regular service or even in between services. Find out more by contacting Downtown Toyota’s service department on 07 3896 0199 we also service all makes and models.
What is AdBlue in a bit more detail:
AdBlue is a diesel exhaust fluid (DEF) consisting of 32.5% high-purity urea and 67.5% deionised water. It’s used in Selective Catalytic Reduction (SCR) systems to reduce NOx emissions in compliance with emission standards. The fluid is injected into the exhaust stream, where it facilitates a chemical reaction that transforms harmful nitrogen oxides into nitrogen (N₂) and water (H₂O). This is critical in modern diesel engine technology for meeting emissions regulations without compromising engine performance or fuel economy.
View the quick video from TotalEnergies for a visual explanation of how AdBlue works.
How Does AdBlue Work?
AdBlue is introduced into the exhaust stream upstream of the SCR (Selective Catalytic Reduction) catalyst. Under high temperatures, the urea in AdBlue decomposes into ammonia (NH₃) and carbon dioxide (CO₂). Inside the SCR catalyst, ammonia acts as a reducing agent and chemically reacts with nitrogen oxides (NOx) in the exhaust gas. The chemical reaction converts NOx into nitrogen (N₂) and water vapour (H₂O), both of which are non-polluting and naturally occurring in the atmosphere. This precise process ensures diesel vehicles meet legal emission limits while optimising fuel efficiency and engine longevity.
How Do I Know If My Vehicle Needs AdBlue?
If you drive a modern diesel vehicle, there's a good chance it needs AdBlue. The easiest ways to check are:
- Look for a blue AdBlue filler cap usually found next to your diesel fuel cap, under the bonnet, or in the boot area.
- Check your dashboard many vehicles display a warning light when AdBlue levels are low.
- Read your owner’s manual as it will confirm whether your car uses AdBlue.
- Ask your dealership if you're unsure, Downtown Toyota can help check for you.
Most newer diesel cars, SUVs, utes, vans, and trucks in Australia use AdBlue as part of a system called SCR (Selective Catalytic Reduction) to meet strict emissions laws. If your vehicle needs AdBlue and runs low, it may not start until it’s topped up.
Common diesel models that require AdBlue include:
- Toyota LandCruiser Prado
- Toyota HiAce (Diesel models)
- Toyota Hilux (Specific variants)
- Ford Ranger
- Mitsubishi Triton
- Heavy-duty trucks and buses
- Agricultural and construction equipment
What Happens If Your Vehicle Runs Out of AdBlue?
Running out of AdBlue isn’t just bad for emissions — it can stop your vehicle from running altogether.
Most modern diesel vehicles are designed with emissions control systems that require AdBlue to operate. If the system detects that the AdBlue tank is empty, your car may:
- Enter ‘limp mode’, significantly reducing engine power to limit emissions.
- Display a warning message with a countdown of how many kilometres you can drive before the engine won’t restart.
- Refuse to start altogether once the AdBlue tank is empty — even if the engine is otherwise in perfect condition.
This is done intentionally by manufacturers to ensure vehicles stay compliant with emissions laws. In most cases, the vehicle will only become operational again once AdBlue is topped up and the system recognises the refill, which may require a short drive or restart cycle.
To avoid this situation, always top up AdBlue as soon as you see a warning light or message. If you're unsure how, or need help, Downtown Toyota’s service department can check and refill your AdBlue any time, just give us a call on 07 3896 0199 or ask during your next visit.
How Often Do I Need to Refill AdBlue?
How often you’ll need to top up your AdBlue depends on your vehicle, driving habits, and mileage. Most diesel passenger cars require a refill approximately every 5,000 to 10,000 kilometres. Fortunately, your car will usually give you plenty of warning — often through a dashboard alert or even a mileage countdown until AdBlue runs out.
Where Can I Get AdBlue?
Finding AdBlue in Brisbane is straightforward, whether you prefer to top it up yourself or let a service centre handle it for you.
If you are comfortable with the DIY approach, automotive retailers such as Supercheap Auto, Repco, and even Bunnings stock AdBlue often in convenient 10-litre containers. These bottles are perfect for home top-ups and are widely available across most Brisbane locations.
If you’re already out on the road, it’s common for most service stations to offer AdBlue. You’ll find it either packaged on the shelf near engine oils and car care products, or available at the pump. For example, AdBlue is available at select BP and Ampol stations around Brisbane, including Bowen Hills, Newstead, and Camp Hill, all open 24/7. Shell Coles Express locations may also carry AdBlue in-store.
If you prefer to leave things like this to the professionals, you can always have your AdBlue topped up during your next scheduled service or even in between services. At Downtown Toyota, our Toyota service department in Brisbane is happy to check your levels and refill AdBlue during you vehicle’s service appointment or for a quick stop in between services. Simply ask when booking or when you drop your vehicle off.
How to Refill AdBlue
Refilling AdBlue is a straightforward process, but it does require a bit of care. Whether you're topping it up at home or at a service station, knowing the proper steps will help keep your vehicle running smoothly and emissions compliant.
Step 1: Park Safely and Switch Off the Engine
Before you begin, make sure your car is parked on level ground and the engine is turned off. This ensures safety and helps avoid any splashes from hot components.
Step 2: Locate the AdBlue Filler Cap
In most vehicles, the AdBlue filler cap is positioned next to the diesel fuel cap, usually marked in blue. However, depending on the make and model, it may also be found under the bonnet or in the boot. It's always best to check your owner’s manual for the exact location.
Step 3: Use Certified AdBlue Only
Always use a high-quality certified AdBlue product. Using anything else can damage your vehicle’s SCR (Selective Catalytic Reduction) system and affect emissions performance. AdBlue is available in bottles with nozzles or at the pump in select service stations.
Step 4: Fill with Care
If you’re using a bottle:
- Attach the nozzle or funnel securely to avoid spills.
- Pour slowly into the tank to prevent overfilling or splashing.
If you're at a petrol station with a dedicated AdBlue pump:
- Insert the AdBlue nozzle into the filler neck, just like you would with fuel.
- Fill until the tank is adequately topped up, then remove the nozzle and close the cap tightly.
Step 5: Finish Up
AdBlue is non-toxic but can irritate the skin and damage paintwork or certain materials if spilled. Be sure to wash your hands and arms thoroughly after handling it, especially if there was any contact with the fluid. If AdBlue comes into contact with your skin, rinse the area immediately with water.
Once filled, replace the AdBlue cap securely. Start your engine and check that any AdBlue warning light on the dashboard has cleared. In some vehicles, it may take a short drive for the system to register the refill.
Need a Hand with AdBlue? Contact Brisbane’s Downtown Service Department Today
If topping up AdBlue feels like too much hassle, you don’t need to stress, the team at Brisbane's Downtown Toyota new and used car dealer is here to help.
While AdBlue is usually considered an owner-maintained item (similar to checking tyre pressure or refuelling), we know it’s not something everyone wants to deal with. That’s why we’re happy to check your AdBlue levels during your regular service and let you know if a top-up is needed. If your dashboard warning light is already on, just mention it when booking or dropping off your vehicle, and we’ll take care of the rest.
Keep in mind that since AdBlue isn’t included in most standard service checklists, there may be a small additional charge if a refill is required, but we’ll always check with you first before going ahead.
If you have any questions or need assistance with AdBlue, give our friendly service team a call on 07 3896 0199, or submit your details in the form below and we’ll be happy to help.