AdBlue® has become standard on many modern diesel vehicles, it is important to understand that not all engines are compatible with this technology.
AdBlue® is generally required in Euro 4, Euro 5, Euro 6 and newer emission standard diesel vehicles. There are some cases where the use of AdBlue® is not required, for example, older diesel vehicles: Diesel vehicles manufactured before 2004 are generally not equipped with SCR (Selective Catalytic Reduction) systems. Furthermore, non-road vehicles such as small diesel engines used in construction equipment and generators still do not require AdBlue® if their emissions are already below the permitted limits. Then some diesel vehicles are equipped with DPF systems to filter soot from the exhaust gas. These DPF systems can work effectively without AdBlue® in some cases, with different levels of emission reduction effectiveness.
Vehicles that require AdBlue® are designed with an SCR system. The SCR system consists of several components, including the AdBlue® tank, AdBlue® pump, AdBlue® injector, and SCR catalyst. The system works by injecting AdBlue® into the hot exhaust gas in front of the SCR catalyst.
Commercial vehicles such as trucks and buses are the main users of AdBlue® because they are often used in long-distance operations and receive great benefits from reduced NOx emissions to comply with increasingly stringent emission regulations.
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In addition, modern diesel passenger cars, especially those manufactured after the implementation of Euro 4 emission standards, are generally equipped with SCR systems and require the use of AdBlue®. Industrial and construction diesel engines, such as power generators and heavy equipment, are also often equipped with SCR systems and use AdBlue® to comply with emission regulations applicable in various countries.