The Volkswagen Golf 1.9 TDI 90hp (Mk5 - 2003 - 2008) produces 90bhp and 210Nm in standard form. Our Stage 1 ECU tuning file raises output to 149bhp and 320Nm, a gain of 59bhp and 110Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.