The Mercedes SLK 350 - 306hp (R172 - 2011 ->) produces 306bhp and 370Nm in standard form. Our Stage 1 ECU tuning file raises output to 320bhp and 390Nm, a gain of 14bhp and 20Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.