The Mercedes C 300 - 258hp (W205 - 2018 - 2021) produces 258bhp and 370Nm in standard form. Our Stage 1 ECU tuning file raises output to 275bhp and 450Nm, a gain of 17bhp and 80Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.