The Mercedes CLK 430 - 279hp (W208 - 1997 - 2002) produces 279bhp and 400Nm in standard form. Our Stage 1 ECU tuning file raises output to 300bhp and 425Nm, a gain of 21bhp and 25Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.