The American branch of German firm RENNtech, located in Florida, has begun developing a power package for the Mercedes AMG GT S. In the first phase of modifications, RENNtech Mercedes AMG GT undergoes software upgrade with astounding results.

The software for RENNtech Mercedes AMG GT has been developed in Germany, on the Autobahn and the Nurburgring. With a few adjustments in the U.S. it extracts an extra 80 PS from the GT’s 4.0 liter bi-turbo V8 on pump fuel, for a total output of 591 horsepower and 693 Nm of torque.

If you want to know what that power means in terms of raw performance, check out this video:

What we like about this tuner is how thorough they are in the work they do. In the case of the RENNtech Mercedes AMG GT, even though it’s just a software upgrade for now, they went to the trouble of testing the car on the Autobahn, on the dyno, and on the drag strip. As for future upgrades, you can expect a sport exhaust system and maybe even a nice styling kit.

Just to recap, RENNtech’s GT managed 591 PS on dyno, 313 km/h on the autobahn, and 11.28 sec at 128.11 mph at the drag strip.