The Mercedes C 300d 245hp (W205 - 2018 - 2021) produces 245bhp and 500Nm in standard form. Our Stage 1 ECU tuning file raises output to 270bhp and 560Nm, a gain of 25bhp and 60Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.