The Mercedes GT Roadster S 4.0 - 522hp (2017 ->) produces 522bhp and 670Nm in standard form. Our Stage 1 ECU tuning file raises output to 575bhp and 820Nm, a gain of 53bhp and 150Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.