The Mercedes C 350 CDI 231hp (W204 - 2010 - 2014) produces 231bhp and 540Nm in standard form. Our Stage 1 ECU tuning file raises output to 290bhp and 630Nm, a gain of 59bhp and 90Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.