The Audi RS6 4.0 TFSI Performance 621hp (C8 - 2020 ->) produces 621bhp and 850Nm in standard form. Our Stage 1 ECU tuning file raises output to 700bhp and 970Nm, a gain of 79bhp and 120Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.