The Mercedes SLK 55 AMG 360hp (R171 - 2004 - 2010) produces 360bhp and 510Nm in standard form. Our Stage 1 ECU tuning file raises output to 385bhp and 535Nm, a gain of 25bhp and 25Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.