The Volvo Group’s new generation of diesel engines are fueloptimised and have an exceptionally high efficiency rating. The low Euro 4 and Euro 5 particulate emission levels are secured in the initial combustion stage. Nitrogen oxides are dealt with postcombustion, using SCR (Selective Catalytic Reduction). With this method, a blend of urea and deionised water known as AdBlue is sprayed into the hot exhaust gases. This mixture then passes through a catalytic converter where the nitrogen oxides are transformed into harmless nitrogen gas and water vapour. The technology is simple, robust and reliable, and it does not affect the engine’s function.