What technology is used in the Audi A5 to reduce emissions?

I recently learned about how important it is to reduce vehicle emissions for the environment. I am considering purchasing an Audi A5 and am curious about the technology they use to help reduce emissions. Can anyone provide more information about this?

The Audi A5 uses an innovative Selective Catalytic Reduction (SCR) system to reduce harmful emissions of nitrogen oxides. This system injects a urea solution, called AdBlue, into the vehicle's exhaust to break down and convert the nitrogen oxide into harmless nitrogen and water.

In addition to the SCR system, the Audi A5 also features a lightweight construction using aluminum and high-strength steel, as well as an aerodynamic design. These features help to improve fuel efficiency and reduce emissions.