The Audi S6 3.0 TDI 347hp (C8 - 2019 ->) produces 347bhp and 700Nm in standard form. Our Stage 1 ECU tuning file raises output to 380bhp and 840Nm, a gain of 33bhp and 140Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.