The Mercedes CLS 63 AMG Bi-Turbo 525hp (C218 - 2010 - 2014) produces 525bhp and 700Nm in standard form. Our Stage 1 ECU tuning file raises output to 620bhp and 900Nm, a gain of 95bhp and 200Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.