The current Audi TT-RS is powered by a 2.5-liter, 5-cylinder engine that delivers a total of 360 horsepower at 5,500 rpm and 343 pound-feet of torque at a super-low 1,650 rpm. Impressive results for such a tiny sports car, but not impressive enough considering that Mercedes obtained an almost similar output from an even slower engine: the 330 HP 2.0-liter four-cylinder set to be used in the A45 AMG.
As a result, Audi decided its time to update this famous engine. The timing’s right, too, because by September 2014, the German automaker will have to comply to EU 6 regulations. In order to achieve this update, Audi will be working on the engine’s combustion processes, while also working on the catalysts and "from there it’s just geometry", according to quattro development boss Stephan Reil, who also added that the "air coming in to the cylinder in rolling waves to produce as little pollution as possible."
During the entire process, Audi will also be working on improving the engine’s performance numbers, especially if you consider that Tobias Moers from AMG claims that the A45 AMG is around six seconds faster around the Nurburgring Nordschleife than the RS3 - which is also using the five-cylinder engine.