The BMW 6 Series 635D 286hp (E63 - 2004 - 2010) produces 286bhp and 580Nm in standard form. Our Stage 1 ECU tuning file raises output to 332bhp and 685Nm, a gain of 46bhp and 105Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.