Selective Catalytic Reduction (SCR) systems provide a new and efficient method of as well as reducing emissions.It functions by injecting a liquid defluoriser, which combines with NO/over the chemical reaction. There is no practical way at present for the substance to enter the production phase without being dissolved in urea or a similar carrier in order to catalyze transformation. Pressurization systems would come from an auxiliary supply of fresh air. Direct injection ranges all the way from homogeneously lean to diesel fuel systems with up to 100 bar fuel pressure. Electronic control of the whole system by means of advanced sensors is combined with an optimized extraction system for all fluids discharged from engines. The results so far are quite encouraging, with little sign yet apparent as to what they show on an international competition level (since everyone else is still trying out different techniques anyway ).Featuring advanced sensors and a dosing system for the urea-based reduction agent, SCR is equipped more catalytic converter in every detail. In a wide variety of applications, ranging from long-distance truck and bus transport to the field of construction machinery or diesel engines, SCR means that these diesel engines comply with strict emissions regulations at the same time as demonstrating fuel efficiency and power.