The Mercedes S 65 AMG V12 Turbo 630hp (W221 - 2005 - 2013) produces 630bhp and 1000Nm in standard form. Our Stage 1 ECU tuning file raises output to 670bhp and 1100Nm, a gain of 40bhp and 100Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.