In today’s world of increasingly stringent environmental regulations, automotive technology continues to evolve to reduce emissions. One such solution is AdBlue, which plays a key role in reducing pollutants in the exhaust of diesel vehicles. Many drivers encounter the name for the first time and wonder, «AdBlue que es?» and «Why does my car even need it?». Let’s break it down.
AdBlue is the trade name for an aqueous solution of urea (32.5% urea and 67.5% demineralized water). It is important to realize that it is not a diesel fuel additive. It is poured into the vehicle’s separate tank and used in the Selective Catalytic Reduction (SCR) system to convert the nitrogen oxides (NOx) produced during diesel combustion into harmless nitrogen and water.
The use of AdBlue is a necessity for many modern diesel vehicles that meet the Euro-5 and Euro-6 environmental standards. These standards place stringent requirements on nitrogen oxide emissions, and AdBlue is an effective means of reducing them. Without it, the vehicle will either not meet the requirements or will simply not start.
How does SCR with AdBlue work?
 SCR (Selective Catalytic Reduction) is a technology that uses AdBlue to reduce NOx emissions. The process works as follows: the exhaust gases from the engine pass through a catalytic converter where AdBlue is injected into the exhaust system.
 In the catalyst, the urea from the AdBlue is decomposed into ammonia (NH3) and carbon dioxide (CO2) at a high temperature. The ammonia then reacts with nitrogen oxides (NOx) in the exhaust gases, converting them into nitrogen (N2) and water (H2O) – substances that do not pollute the atmosphere.
 This process significantly reduces the amount of harmful NOx in the exhaust gases, making diesel cars more environmentally friendly. The SCR system is very efficient, and thanks to it, diesel engines can meet strict environmental regulations.
Advantages of use
 The main advantage is a significant reduction in nitrogen oxide emissions, which makes the air cleaner and improves the environmental situation. This is especially important in densely populated cities, where a high concentration of cars leads to air pollution.
 In addition, the use of AdBlue improves the fuel economy of the vehicle. This is due to the fact that the SCR system allows optimizing engine operation to achieve more efficient combustion.
 Finally, compliance with environmental standards (Euro-5, Euro-6 and above) allows the vehicle to travel freely in environmental zones where there are restrictions on the entry of high-emission vehicles.
Where can it be found and how can it be refilled?
AdBlue is available at most car dealerships, gas stations and even large supermarkets. It is sold in canisters of varying volumes and may also be available for refilling from a special dispenser at gas stations.
AdBlue is filled into a separate tank, usually located next to the fuel tank. In some vehicles, the AdBlue refueling hatch may be located in the trunk or under the hood. It is important to use a special funnel to avoid spilling AdBlue, which could damage the car’s paintwork.
The AdBlue level must be checked regularly. If the level is low, a warning light will illuminate on the dashboard. Ignoring this warning may result in the vehicle not starting, as the engine management system will block the engine if there is no AdBlue in the vehicle.
What happens if AdBlue is not refueled?
As already mentioned, modern diesel vehicles that meet Euro 5 and Euro 6 standards cannot run without AdBlue. The engine management system monitors the level of fluid in the tank and if AdBlue is missing or insufficient, the engine will stall.
Trying to bypass this system can lead to serious problems. Firstly, it is illegal and can result in a fine. Secondly, it will lead to a significant increase in NOx emissions, negating any efforts to improve the environment. Third, it can damage the SCR system and lead to costly repairs.
Ultimately, regular refueling is a prerequisite for the operation of modern diesel vehicles, and neglecting this requirement can lead to serious problems and financial losses.
Tips for use
Do not use it if the expiration date has expired. It is usually about 1-2 years if stored properly. Do not store it in direct sunlight or at extreme temperatures.
Do not replace AdBlue with other fluids or additives. This may cause damage to the SCR system. Always use only original AdBlue that complies with ISO 22241.
Check the AdBlue level regularly and replenish it in good time. Do not allow the tank to be completely empty to avoid starting problems.
By following these simple tips, you will keep your SCR system running smoothly and help reduce emissions, making the world a cleaner place for yourself and future generations.