The BMW 3 Series GT 335i 306hp (F34 - 2012 - 2015) produces 306bhp and 400Nm in standard form. Our Stage 1 ECU tuning file raises output to 365bhp and 520Nm, a gain of 59bhp and 120Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.