The Mercedes CLS 500 - 408hp (C218 - 2014 - 2018) produces 408bhp and 600Nm in standard form. Our Stage 1 ECU tuning file raises output to 510bhp and 850Nm, a gain of 102bhp and 250Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.