Many new diesel cars use a fluid called AdBlue. If your car uses AdBlue, you'll probably need to top it up at least once between services.
Find out what it does, how it works and why it’s important to keep an eye on dashboard warnings - particularly if you’re a high mileage motorist.
What is AdBlue?
AdBlue is an exhaust fluid, not a fuel additive. It's stored in a separate reservoir and is topped up via a (usually) blue filler cap located either next to your fuel filler, in the boot or under the bonnet.
It's a trade name registered by the German car manufacturers association, but is the most recognised form of Diesel Exhaust Fluid (DEF).
What is AdBlue made of?
AdBlue is a colourless, non-toxic mixture of urea and de-ionised water. It’s not actually blue at all.
Lots of people think AdBlue is made of pig urine – it’s not. The urea used in AdBlue is a high purity man-made solution – pig urine wouldn’t be pure or sterile enough for a commercial product.
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How does AdBlue work?
Tiny amounts of AdBlue are injected into the flow of exhaust gases. At high temperatures AdBlue turns to ammonia and carbon dioxide.
Inside the SCR (Selective Catalytic Reduction) catalyst, harmful nitrogen oxide in the exhaust reacts with the ammonia and is transformed to harmless nitrogen and water.
Similar technology has been used effectively for years in buses and heavy lorries.
Need breakdown cover? Read our guide about how it works:
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What happens if I run out of AdBlue?
If you run out of AdBlue while you’re driving, then the engine’s power and performance will be reduced to limit its emissions. Once you’ve stopped, you won’t be able to restart the engine if the AdBlue tank’s empty.
The car will give you plenty of warning that the AdBlue tank’s running low. You'll usually see a text warning on the dashboard at around 1500 miles to go followed by an amber warning light.
Which cars can use AdBlue?
Not all car manufacturers use AdBlue technology. But chances are if you’ve got a diesel from Jaguar, Land Rover or any French or German manufacturer, and it was registered new after September 2015, it’ll use AdBlue.
Does my car use AdBlue?
Some older cars or vehicles from other manufacturers use AdBlue too. So if you’re not sure if your car uses it, you can check:
- The vehicle handbook.
- See if there’s an AdBlue filler cap either next to the fuel filler, in the boot or under the bonnet.
- If the model name contains ‘Blue’ or ‘SCR’.
- If you’re still not sure, ask a dealer.
Where can I buy AdBlue?
AdBlue’s sold by petrol stations, garages, motor accessory shops, online retailers and even some supermarkets. If you’re in any doubt that you’re buying the right stuff, contact your dealer.
It’s widely available in 1.5, 5 and 10 litre containers. The smaller packs have a specially-designed neck that lets you top up the tank without risk of spillage even if you don't have a funnel.
With easy-fill bottles available, it's a good idea to carry a small container of AdBlue so you’re ready to top-up when necessary.
How long does AdBlue last?
The rate at which you use AdBlue depends on your engine and how economically you drive.
- Typical consumption is around a litre of AdBlue every 600 miles.
- But it could be as high as a litre every 350 miles.
- Tank size varies too, so you could need to refill somewhere between 3,000 and 12,000 miles depending on the car and your driving style.
This means that most drivers will have to top-up their AdBlue reservoir at least once between normal service visits to the dealer.
Is it safe to drive with the AdBlue warning light on?
It’s not a major safety issue, but if you don’t top up, you’ll eventually run out of AdBlue and you won’t be able to start the car.
When the warning light first comes on you’ll have plenty of time to refill – so don’t panic. Just make sure you don’t put off topping up, especially if you’re about to book an MOT test. Your vehicle’s emissions will be checked as part of the MOT – not having the right amount of Adblue could increase them to a dangerous level.
How to reset the AdBlue warning light
There’s no manual way of resetting your AdBlue warning light – the only thing you can do is top up. Once you’ve refilled to the minimum level, the warning light will disappear.
Where is the AdBlue tank?
The AdBlue tank is usually located under the boot floor, where the spare wheel might have been in the past. But it's more important to know where the filler for it is located.
There'll usually be a small blue filler cap next to the main diesel filler. If it's not there, then check in the boot or under the bonnet.
What happens if I put AdBlue in the diesel tank?
Putting it directly into your fuel tank could cause expensive damage to your fuel tank, pump and injection system. If you start the engine it's likely to be an expensive write-off, so don’t touch the ignition.
You’ll need to get the tank drained and the contents disposed of safely before you can refill it. Call us, and we’ll sort the problem out.
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What happens if I put diesel in the AdBlue tank?
Don’t turn on the ignition or start the engine and call us for help.
If you do start your engine, then the damage could mean that you have to get the entire Selective Catalytic Reduction and AdBlue injection system replaced.
How do I refill the AdBlue tank?
- Follow any instructions given in your handbook or on the pack.
- Your handbook will tell you how much AdBlue the tank holds.
- 5 litres should be enough to make sure your car will restart if you’ve run out completely.
- You may need a funnel depending on where the AdBlue filler cap is located (next to the fuel filler, in the boot, or under the bonnet) and the size or design of the AdBlue pack you’ve got.
- Wash your hands and rinse any spills from the bodywork – AdBlue’s non-toxic but can cause irritation to your skin and eyes and will damage the paintwork.
How does AdBlue reduce exhaust emissions?
AdBlue is added to your exhaust and mixes with the fumes your car produces. It reacts with nitrogen oxide gas (NOx gas) created by your engine and breaks it down into harmless nitrogen and water vapour.
NOx gases cause respiratory problems and contribute to the formation of particulate matter, smog, acid rain and ground level ozone.
Vehicles have to meet strict exhaust emissions limits and the latest standard, Euro 6, is very challenging on Nitrogen Oxide (NOx) limits.
Most cars can only meet the Euro 6 standard when fitted with emissions technology known as Selective Catalytic Reduction (SCR). This technology uses AdBlue to break down and reduce harmful emissions.
Published: 1 May 2017 | Updated: 28 January 2020 | Author: The AA
What happens if your car runs out of AdBlue? If you run out of AdBlue while you’re driving, then the engine’s power and performance will be reduced to ‘limp home’ mode to limit its emissions and once the engine has stopped, it won’t re-start until the AdBlue tank is refilled.
Do petrol cars need AdBlue? AdBlue is sold in all the usual places such as Halfords and most petrol stations. The AdBlue tank will always be separate to the fuel tank. Most diesel vehicles which use AdBlue will have a driver information display which will let you know when AdBlue levels are getting low.
Can I refill AdBlue myself? Yes, you can top up with AdBlue® yourself. Every TotalEnergies service station sells standard 5L and 10L cans of AdBlue®. TotalEnergies is also gradually deploying special pumps for light vehicles. Never top up with a pump for heavy goods vehicles.
Is AdBlue expensive?
The price of AdBlue starts at roughly £5 for a 4.7-litre container, at the time of writing. Some car makers, including Peugeot, suggest you take the car to a dealer, which will do a refill for a fixed price of £9.99. Vauxhall offers to waive any labour charge if drivers bring their car in for a top-up.
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How much AdBlue should I add?
It is difficult to say exactly how much AbBlue® your car needs as models differ, but usage generally equates to around 1 litre per 350 to 600 miles. AdBlue® use is also usually around 3 to 6% of diesel consumption. The amount your car needs is dependent on engine size, driving style and the size of the AbBlue® tank.
Is AdBlue made from pigs urine?
Is AdBlue® made from pigs’ urine? AdBlue® is a synthetic, highly purified solution of urea and demineralized water NOT pigs urine. Whilst the chemical urea is in pigs’ urine, it is found in much lower concentration alongside many other elements.
Do all new diesel cars use AdBlue?
Not all car manufacturers use AdBlue technology. But chances are if you’ve got a diesel from Jaguar, Land Rover or any French or German manufacturer, and it was registered new after September 2015, it’ll use AdBlue.
Can you put too much AdBlue in a car?
Do not overfill the AdBlue reservoir. On some cars, the AdBlue pump and circuitry are located on top of the tank, so overfilling risks moisture contamination that can damage the circuits.
Can you top up AdBlue anytime?
AdBlue is not injected into the engine as a fuel additive. The size of AdBlue tanks vary, too, so when you need to top up depends on your driving style, the number of miles you cover, and the size of the tank. A dashboard warning light will let you know when it is time to top up.
Can I buy AdBlue at petrol stations?
You can find portable containers of AdBlue in the majority of filling stations, at the majority of appropriate retailers and the big branded online platforms too.
How do I check my AdBlue level?
When the AdBlue level starts to become low, a symbol illuminates in the driver display and the AdBlue level low message is shown. Open the fuel filler flap with a gentle press on the rear of the flap. Open the blue cover for the smaller filler pipe intended for AdBlue. Fill with AdBlue of the correct quality.
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Is there different types of AdBlue?
AdBlue is a proprietary name, like Hoover and iPhone: i.e. there are not different types or brands of AdBlue, though there may at any time be different brands selling other urea-based solutions that perform the same function. AdBlue is stored in a tank in the vehicle, and is injected into the SCR system as required.
Is there an alternative to AdBlue?
Using water instead of AdBlue – In short, you mustn’t use water instead of AdBlue, or water down the AdBlue in anyway. AdBlue is a mixture of urea and 67.5% de-ionized water. Where as tap water contains a lot of minerals and ions that is harmful to the vehicle exhaust treatment system.
Is all AdBlue the same quality?
Is all AdBlue® the same? While there are different names for AdBlue®, such as Bluedef, BlueTec and so forth, all mixes should contain the same solution of 32.5% urea and 67.5% de-ionised water. The VDA notes that vehicles should not use urea solutions not denoted by the ‘AdBlue’ trademark.
Is there a difference in quality of AdBlue?
It is important to notice that not all AdBlue present in the market has the same quality. These problems are also going to become more frequent thanks to the increase in AdBlue consumption in the new Euro 6 engines, from an initial 1-2% to about 3-5%.
How do I know when AdBlue tank is full?
Simply tip the solution into the car and when you’re full, you’re full! Most vehicles with AdBlue will have a gauge of how full the tank is buried somewhere in the car’s infotainment. Keep searching until you find it, and you’ll know how much AdBlue you need.
How long should AdBlue last?
How long does AdBlue last? According to GreenChem, a typical mid-sized diesel car will travel 1,000km (620 miles or so) on a single litre of AdBlue. Most AdBlue tanks hold around 10 litres or more, so you may find it won’t need to be topped up until the next scheduled service.
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How big is the AdBlue tank?
Bulk AdBlue Storage Tanks typically have a capacity of 1,000 litres or greater and are fully bunded to ensure compliance with all applicable environmental safety requirements.
How long does AdBlue last once opened?
What is the shelf-life of AdBlue fluid? AdBlue can last up to 18 months in storage. To keep AdBlue in its optimal condition, store it: out of direct sunlight.
What happens if you put diesel in AdBlue tank?
A single drop of Diesel can contaminate several litres of AdBlue®. If you start up with an AdBlue® tank filled with Diesel, you risk causing very serious damage to your vehicle’s SCR system. If you do start up, you vehicle will begin to behave strangely.