The BMW XM 4.4 Bi-Turbo V8 748hp (2022 ->) produces 748bhp and 1000Nm in standard form. Our Stage 1 ECU tuning file raises output to 850bhp and 1100Nm, a gain of 102bhp and 100Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.