The Mercedes CL 63 AMG 525hp (C216 - 2006 - 2010) produces 525bhp and 630Nm in standard form. Our Stage 1 ECU tuning file raises output to 555bhp and 660Nm, a gain of 30bhp and 30Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.