The BMW 1 Series M135i 306hp (F40 - 2019 ->) produces 306bhp and 450Nm in standard form. Our Stage 1 ECU tuning file raises output to 335bhp and 500Nm, a gain of 29bhp and 50Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.