The Audi A8 4.2 FSI 372hp (D4 - 2010 - 2016) produces 372bhp and 445Nm in standard form. Our Stage 1 ECU tuning file raises output to 392bhp and 470Nm, 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.