The Audi A8 S8 4.2 V8 360hp (D2 - 1999 - 2003) produces 360bhp and 430Nm in standard form. Our Stage 1 ECU tuning file raises output to 380bhp and 455Nm, a gain of 20bhp and 25Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.