The Audi A8 4.0 TFSI 435hp (D4 - 2010 - 2016) produces 435bhp and 600Nm in standard form. Our Stage 1 ECU tuning file raises output to 540bhp and 800Nm, a gain of 105bhp and 200Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.