The Mercedes CLS 400 - 333hp (C218 - 2014 - 2018) produces 333bhp and 480Nm in standard form. Our Stage 1 ECU tuning file raises output to 400bhp and 580Nm, a gain of 67bhp and 100Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.