The BMW 5 Series 520i 150hp (E39 - 1995 - 2003) produces 150bhp and 190Nm in standard form. Our Stage 1 ECU tuning file raises output to 165bhp and 208Nm, a gain of 15bhp and 18Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.