The Audi A8 4.2 TDI 326hp (D3 - 2003 - 2010) produces 326bhp and 650Nm in standard form. Our Stage 1 ECU tuning file raises output to 380bhp and 880Nm, a gain of 54bhp and 230Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.