AdBlue® FAQs

1. What is AdBlue®?

AdBlue® is an aqueous solution comprised of 32.5% high purity urea* and of 67.5% deionised water, it respects the ISO22241 norm. Urea is synthetically produced from ammonia and CO2 (carbon dioxide). AdBlue® is used by vehicles equipped with the SCR technology (Selective Catalytic Reduction), such as heavy-duty trucks, buses, refuse collection vehicles, and from September 2014, certain diesel passenger cars. Biodegradable, soluble in water, and colourless, AdBlue® cristallises at -11°C and decomposes into ammonia from 80°C (traces from 30°C). AdBlue® is a registered trademark of the German Association of the Automobile Indutry (VDA).
*What is urea?
Urea is a product from the agrochemical industry, mostly used for fertilizer production. It is produced from ammonia (NH3) and carbon dioxide (CO2). Its chemical formula is CO(NH2)2. When heated, urea decomposes into gaseous ammonia. It is under this state that is transforms the nitrogen oxides (NOx) into nitrogen and into water (N2, H2O).

2. What is the use of AdBlue®?

Combined to the SCR technology, AdBlue® transforms 85% of NOx (nitrogen oxides resulting from the exhaust gases of your diesel vehicle) into harmless nitrogen and water steam. Therefore, NOx, which are a major source of atmospheric pollution are drastically reduced.

3. Euro 5 and Euro 6 norms: why do I need AdBlue®?

To improve the air quality, the European Union regulates since 1990 the polluting emissions of exhaust gases throughout various European directives and regulations. Since this date, several norms (Euro 1 to Euro 6) have been implemented in order to set lower and lower emissions limits.

These anti-pollution European norms aim at reducing harmful emissions from exhaust gases, such as nitrogen oxides (NOx), hydrocarbons, carbon monoxide, and particulate matter. The SCR technology using AdBlue® is one of the systems elected to meet the EURO norms objectives and reduce polluting emissions.

4. What is the SCR technology?

SCR (Selective Catalytic Reduction) is the name of a post-combustion treatment technology for Diesel vehicles, converting nitrogen oxides (NOx) into water steam and nitrogen thanks to the ise of AdBlue®. The air we breathe is composed of 80% nitrogen, which is completely harmless. With the heavy-duty vehicles emissions European Norms Euro 4 and Euro 5, almost all car manufacturers have decided to use this technology to respect the new legislations on NOx emissions. For passenger cars, SCR is only appearing in Europe from 2014 with the Euro 6 norm.

AdBlue® is injected into the exhaust pipe, located before the SCR catalyst and after the engine. When heated inside the exhaust pipe, AdBlue® decomposes into ammonia (NH3) and into carbon dioxide (CO2). When the NOx react with the ammonia inside the catalyst, the harmful NOx molecules are transformed into harmless nitrogen (N2) and into water (H2O).

5. Is my vehicle equipped with SCR technology?

To find out if your car is equipped with SCR technology, please see your vehicle’s owner manual or contact your dealership. If you notice an AdBlue® tank on your car, located next to the diesel tank filler neck, then your car is equipped with SCR.

6. Where is my AdBlue® tank filler neck?

The location of the AdBlue® tank filler neck depends on the model of your vehicle. On certain models, the AdBlue® tank filler neck is next to the Diesel filler neck. On others, the AdBlue® filler neck is inside the boot, and on other vehicles, the filler neck is under the bonnet. To get this information, contact your dealership, or see the owner manual of your vehicle.

7. What is the capacity of the AdBlue® tank?

The capacity of the tank also depends on the model of your vehicle. In general, it varies between 8L and 25L. To get this information, contact your dealership, or see the owner manual of your vehicle.

8. What if the frequency of AdBlue® refill?

As with fuel, several factors have an impact on consumption: the type of vehicle, the engine type, the vehicle load, the weather conditions (snow, wind, rain, etc.) and the driving style. Moreover, the size of the AdBlue tank varies considerably, so the refill frequency depends particularly on the vehicle.

On heavy-duty trucks, a gauge indicates the level of AdBlue® left in the tank. On passenger cars, a warning light appears on the dashboard when 2400km of driving capacity remain (when this signal appears it is time to refill).

9. Can I refill the AdBlue® tank myself?

Yes, this is possible. However, depending on the vehicle, the AdBlue® tank filler neck is more or less easy to access. Also, some vehicles need to have their dashboards reset to make the AdBlue® warning light disappear, which may require that the car owner still goes to the dealership.

Caution: If you see a service station selling AdBlue®, always ask if the pumps are 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 at the pump. Indeed, heavy-duty trucks must often refill AdBlue®, sometimes weekly, so the station pumps are specifically designed for their use (particularly the flow speed, adapted to the size of their tanks which is much bigger than that of passenger cars).

10. What is the AdBlue® consumption compared to fuel consumption?

As with the fuel consumption, the AdBlue® consumption varies, and depends on several factors: type of vehicle (camper, SUV, car, etc.), type of engine, driving conditions (mountain, with a trailer, caravan, etc.), driving style. For passenger cars sold between 2013 and 2016, the consumption is around 1.5L of AdBlue® every 100L of diesel.

11. Is AdBlue® sold at the service station compatible with my vehicle?

The SCR technology is designed to work with a fluid meeting the ISO 22241 requirements. All AdBlue® labelled products respect this ISO norm, and ensure a smooth functioning of the SCR, whatever the brand of your car.
Car manufacturers only recommend AdBlue® labelled products, although other products may be used without risk for the SCR as long as they respect the ISO 22241 norm.

12. If I refill AdBlue® myself, could I lose the manufacturer’s warranty?

No, 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 ISO 22241 norm. The AdBlue® brand ensures that this norm is respected. 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 or SCR replacement.

13. What are the precautions of use of AdBlue®?

AdBlue® is very easy to use and harmless. It is neither a fuel, nor a fuel additive, but high quality urea solution that must remain into a dedicated tank on your vehicle. You refill the AdBlue® tank according to your needs. Caution: do not put AdBlue® into the diesel tank, or diesel into the AdBlue® tank, this would be very damaging for the engine and the catalyst.

14. Is AdBlue® a dangerous product?

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 on your clothing, simply rinse with water.

15. Does AdBlue® leave stains if I spill some next to the tank?

AdBlue® can leave white stains and/or cause the floor to become slippery. If you spill AdBlue® on the floor, inside a vehicle, or on a painted surface, rinse abundantly with water. If you spill AdBlue® on your skin or on your clothes, you can remove it with water.

16. When does the « refill AdBlue® » warning light appear on the dashboard?

The alert starts 2400km before you need to refill (this alert level is common to all vehicle and required by the norm). Your dashboard includes a warning light which will turn on when you need to refill your AdBlue® tank. If the dashboard signals that a refill must be done, do not worry: you have a driving capacity remaining of many hundreds or thousands kilometres remaining before having to refill AdBlue®. To turn this warning light off, refill the tank with at least 4L of AdBlue®. The format of the canisters offered by TOTAL service stations is therefore particularly well adapted for a quick refill.

17. Is there any other maintenance constraints?

Your car SCR system is installed by the manufacturer, and works automatically. Therefore, you do not need to maintain, or change it. AdBlue® is automatically injected in the exhaust gases according to the engine speed of your vehicle. You can however make sure your SCR system works properly by using only AdBlue® to preserve the efficiency of the SCR catalyst.

18. Does AdBlue® have an impact on the engine performance?

AdBlue® has no direct effect on the functioning of the engine. It helps reducing the polluting emissions to meet the standards of the European norms. However, in case of non-refill of the AdBlue® tank, the performance of the engine can be limited, or the vehicle stopped.

19. Does AdBlue® have an effect on my fuel consumption?

The use of SCR technology and AdBlue® enables the optimisation of combustion, which can lead to a reduction of consumption for some vehicles. This consumption reduction is already integrated into the figures claimed by car manufacturers.

20. What happens if I do not refill the AdBlue® tank?

The first “refill AdBlue®” alert appears at 2400km remaining driving capacity. This timeframe is considered sufficient to allow the driver to refill AdBlue®.
If you do not refill the tank, other alert levels will trigger depending on the distance travelled and the number of engine restarts. First, these alerts will be visual and/or sound. Then the engine performances will be restricted by the vehicle. The last step consists of the impossibility to restart the car without refilling the AdBlue® tank.

21. What happens if I park my vehicle several days outside at a below -11°C temperature?

Car manufacturers have normally taken this case into account and integrated an automatic warming system of AdBlue® in the tank, to allow the SCR catalyst to function properly within 20 minutes after engine start, in accordance with the regulation. If AdBlue® has crystallised in the tank, its performances are not weakened: the warming system will make it become liquid again during the first 20 minutes to ensure that the SCR works properly.

22. What to do after an extended storage period?

AdBlue® product life is superior to a year if it is stored at a temperature below 30°C. However, if the mileage driven by your vehicle is very low in view of the size of the tank, an AdBlue® change and renewal at the dealership should be considered. In that case, refer to your owner manual, or consult your dealership.

23. Evolution of norms?

Anti-pollution European norms for passenger cars and for heavy-duty vehicles evolve as the years go by. Most car manufacturers start installing SCR systems with AdBlue® to meet the objectives of the Euro 6b norm starting end of 2014. They are planning a larger deployment for the Euro 6c norm starting end of 2017.
The NOx level of emissions evolves with the regulation: the AdBlue® consumption of the vehicles produced in 2017 will therefore evolve as well, and reach 3 to 4% of the diesel consumption.


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