AdBlue, or Diesel Exhaust Fluid (DEF), is a product known worldwide as AdBlue. AdBlue is based on the ISO 22241 standard and consists of pure urea (32.5%) and deionized water (AUS 32) with 67.5%. It is placed in separate tanks inside the vehicle. During fuel combustion, a specific amount of AdBlue is added to the nitrogen oxide catalyst in the engine, reducing the pollutants present in the engine’s exhaust gases. In general, AdBlue is used in Euro 5 and Euro 6 diesel vehicles. This solution is a consumable fluid in the Selective Catalytic Reduction (SCR) system of diesel vehicles and significantly reduces the level of toxic nitrogen oxides (NOx) gases. Due to its importance in reducing air pollution and preserving the environment in most European countries, as well as the stringent regulations in place to limit air pollution, the use of this technology is mandatory in all vehicles compliant with EURO 4, EURO 5, and EURO 6 standards. Overall, the consumption of AdBlue depends on factors such as vehicle usage, vehicle type, driving conditions, and other factors. Therefore, it is important to follow the vehicle manufacturer’s guidelines to know how and under what conditions to use AdBlue and how to monitor its level in your vehicle.