The Mercedes C 350 V6 Blue Efficiency - 306hp (W204 - 2010 - 2014) produces 306bhp and 370Nm in standard form. Our Stage 1 ECU tuning file raises output to 328bhp and 411Nm, a gain of 22bhp and 41Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.