AdBlue® is a solution made up of 32.5% urea and 67.5% de-ionised water. AdBlue® is kept in a separate designated tank. AdBlue® is injected into the exhaust pipe between the engine and the SCR catalyst. In the SCR (Selective Catalytic Reduction) process its role is as a reduction agent that reacts with, and neutralises, nitrogen oxides (NOx).
It is also known outside of Europe as DEF, ARLA 32 or AUS 32.
AdBlue® is used in SCR technology-equipped vehicles, such as heavy-duty trucks, buses, farming vehicles, ships, trains, passenger cars.
What is AdBlue®?
Is AdBlue® hazardous?
No, AdBlue® is not a hazardous substance. AdBlue® is non-flammable, non-explosive, and harmless for the environment. It is classified as a transportable fluid of minimum risk. If you spill AdBlue® on your hands or your clothing, simply rinse with water.
AdBlue® is a highly purified colourless solution. AdBlue® is corrosive and can dissolve materials that are not listed as AdBlue® proof in ISO 22241. These materials could cause malfunctions in the SCR-catalyst.
Do I need AdBlue® in my car?
AdBlue® is mandatory in diesel cars manufactured since 1 January 2017. If your car is less than 3 years old and is a diesel car, then you may need to fill it with AdBlue®.
To make sure this is the case, you simply have to check your user manual.
Why do I need AdBlue® in my car?
Your vehicle needs AdBlue® to reduce NOₓ emission. Due to the stricter emission legislation, diesel engines need to have cleaner exhaust gases. NOₓ is one of the emissions that causes acid rain. To meet Euro 6 standards for diesel engine emission the use of Selective Catalyst Reduction technology and AdBlue® is required.
All commercial vehicle manufacturers must meet Euro 6 standards for diesel engine emissions. Although Euro 5 emission standards could be met by using different technologies, Euro 6 standards require the use of Selective Catalytic Reduction with AdBlue®.
How to recognise the AdBlue® tank?
You can recognise your AdBlue® tank by its blue cap or an AdBlue® label, but it is a totally separate tank. The filling point is often fitted near diesel cap. Some passenger cars have an AdBlue® tank in the boot or under the bonnet. The opening for AdBlue® tank is narrower than the opening for a diesel tank.
What should I do if I put diesel into my AdBlue® tank?
The most important thing to remember if this happens is not to start your vehicle. Diesel can have an undesirable effect on the SCR system, so putting any quantity of it into your AdBlue® tank could cause a lot of disruption. Switching on your engine will cause the diesel to run through the system, potentially compounding the damage. You will most likely need to have your AdBlue® tank drained to solve the problem. You will have to get in touch with your motor repair service.
What should I do if I put AdBlue® into my diesel tank?
Firstly, do not start your vehicle, as this could cause damage to your fuel system. If you have put a large quantity of AdBlue® into your fuel tank, there is more chance that your vehicle’s fuel system will have suffered harm. Similar to putting petrol into your diesel vehicle, you will need to get the tank drained and dispose of the contents safely before you can refill it. You will have to get in touch with your motor repair service.
What happens when your vehicle runs out of AdBlue®?
If your vehicle runs out of AdBlue®, your SCR system will not be able to function, which will lead to limited vehicle performance or your engine not running at all. The vehicle performance will be restored by refilling the AdBlue® tank. Some engines will not start after you have run out of AdBlue®. Make sure that you have an emergency supply.
The emission limits will also be exceeded. Since diesel engines operate on an optimally tuned fuel consumption principle, this will have a negative impact on NOx emissions. As your vehicle has been manufactured to meet Euro 4, 5, and 6 standards, it is required by law to meet its acceptable emissions level at all times.
Can I refill the AdBlue® tank myself?
Yes, you can. However, depending on the vehicle, it may not be easy to access the AdBlue® tank filler neck. Also, some vehicles need to have their dashboards reset to make the AdBlue® warning light disappear.
Caution! If you see a service station selling AdBlue®, ask if the equipment is designed to refill the tank of a passenger car. That is not always the case. It is likely that only heavy-duty trucks can refill. Since heavy-duty trucks must often refill AdBlue®, the station pumps are specifically designed for their use. The flow rate of AdBlue® is too high for a passenger car. In this case, AdBlue® can be filled, but very carefully and slowly.
If I refill AdBlue® myself, could I lose the manufacturer‘s warranty?
No, you cannot, so you are not taking any risk. However be cautious: most car manufacturers will not accept the warranty claims if you use a product which does not comply with the ISO22241 standard. The SCR systems are extremely sensitive to any chemical impurities in the urea solution. Using a quality product will help you avoid high repair costs of SCR.
Does AdBlue® freeze?
Yes, it does, the freezing point of AdBlue® is -11°C. However, since the AdBlue® tank on most vehicles is next to the exhaust, you shouldn’t have any problems while the engine is running. Vehicles that have the AdBlue® tank situated elsewhere often have a system where it is heated by circulating engine coolant. Even if it does freeze, AdBlue® will work perfectly once it is thawed out.
How much AdBlue® do I need?
The amount of AdBlue® that you need will depend on the type of vehicle you are driving. AdBlue® consumption is determined by many factors including engine load, travel route, engine size and ambient temperature.
AdBlue® consumption by agricultural and off road vehicles varies greatly, due to a wide range of operating conditions and engine demands. A ratio of 5 to 10% of the diesel usage is used to calculate the required AdBlue®.
The average consumption of AdBlue® for tucks is 4 to 8% of the diesel usage.
The mileage of a passenger car is very low compared to a commercial vehicle as is the operating load on the engine. The majority of passenger car SCR systems have been designed with an AdBlue® storage tank large enough to last in between service intervals. It is estimated that a mid-class diesel consumes 1 litre of AdBlue® for 1,000 km. An SUV class diesel – 1.5 litre of AdBlue® for 1,000 km.
How to store AdBlue®?
AdBlue® should be stored out of direct sunlight between -5°C and 25°C in a clean and sealed can or dispensing unit. AdBlue® should only be stored in a clean plastic or stainless steel container. Storing it in the unsuitable equipment may affect the quality parameters of AdBlue® and damage the SCR of a vehicle.