The BMW 5 Series 535i 300hp (E60/61 - 2003 - 2010) produces 300bhp and 407Nm in standard form. Our Stage 1 ECU tuning file raises output to 370bhp and 500Nm, a gain of 70bhp and 93Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.