The Mercedes CLS 220d (2.0D) 194hp (C257 - 2021 ->) produces 194bhp and 400Nm in standard form. Our Stage 1 ECU tuning file raises output to 225bhp and 480Nm, a gain of 31bhp and 80Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.