The BMW 5 Series 540i 4.4 V8 286hp (E39 - 1995 - 2003) produces 286bhp and 440Nm in standard form. Our Stage 1 ECU tuning file raises output to 300bhp and 460Nm, a gain of 14bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.