The Mercedes CLS 250 CDI 204hp (C218 - 2010 - 2014) produces 204bhp and 500Nm in standard form. Our Stage 1 ECU tuning file raises output to 240bhp and 550Nm, a gain of 36bhp and 50Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.