The BMW 5 Series 530i 231hp (E39 - 1995 - 2003) produces 231bhp and 300Nm in standard form. Our Stage 1 ECU tuning file raises output to 246bhp and 325Nm, a gain of 15bhp and 25Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.