The Mercedes CL 63 AMG 544hp (C216 - 2010 ->) produces 544bhp and 800Nm in standard form. Our Stage 1 ECU tuning file raises output to 620bhp and 1050Nm, a gain of 76bhp and 250Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.