Selective Catalytic Reduction | How it works

Selective Catalytic Reduction (SCR) technology uses ammonia to break down dangerous NOx emissions produced by diesel engines into nitrogen and water. In automotive applications SCR delivers ammonia through a urea solution – Diesel Exhaust Fluid (DEF) – which is sprayed into the exhaust stream by an advanced injection system and then converted into ammonia on a special catalyst.

SCR is the technology of choice for the majority of truck and engine manufacturers to meet 2010 emissions standards for heavy-duty trucks.

Aside from helping the environment, the biggest benefit of SCR for vehicle owners is the fuel efficiency the technology provides. Because SCR deals with emissions in the exhaust pipe, engineers are able to tune the engine to provide more torque and reduce fuel consumption.

Selective Catalytic Reduction (SCR) has been widely implemented on diesel vehicles; by the end of 2010, more than 1 million trucks and buses had been equipped with the technology in Europe alone.