The Mercedes CLS 500 Bi-Turbo 407hp (C218 - 2010 - 2014) produces 407bhp and 600Nm in standard form. Our Stage 1 ECU tuning file raises output to 510bhp and 820Nm, a gain of 103bhp and 220Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.