For those who think that the Mercedes CLK 63 AMG Black Series is a little bit soft, you have to find out that Renntech launched its customization programme for the German sports car. Renntech was established back in 1989 by Hartmut Feyhl, an ex technical director of AMG North America and made quickly a name in the world of car tuning.

In order to increase the power of the vehicle the tuner added long-tube headers and a new motorsports style exhaust which with the ECU tweaking pushed the power plant to an astonishing 550 hp, delivering an aditional torque between 2400 and 500 rpm.

"Real-world performance is all about torque, not so much about a peak horsepower number at very high rpm," explains Feyhl. "It can be very easy to build high rpm horsepower, but to get instant throttle response and mid-range acceleration it is more difficult, and this is where customers really want to feel that improvement." The car got also a new suspension kit which lowered it even more and added carbon fiber elements like a new front splitter and rear diffuser to manage the underbody airflow.

With the new customization programme the car is capable to hit 100 km/h in less than 4 seconds while the top speed is over 300 km/h.