The Mercedes CLA 45 AMG S 421hp (C118 - 2019 ->) produces 421bhp and 500Nm in standard form. Our Stage 1 ECU tuning file raises output to 470bhp and 620Nm, a gain of 49bhp and 120Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.