The BMW 5 Series 550i 367hp (E60/61 - 2003 - 2010) produces 367bhp and 490Nm in standard form. Our Stage 1 ECU tuning file raises output to 390bhp and 525Nm, a gain of 23bhp and 35Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.