The BMW 4 Series GC 420D 184hp (F36 - 2014 - 2016) produces 184bhp and 380Nm in standard form. Our Stage 1 ECU tuning file raises output to 220bhp and 440Nm, a gain of 36bhp and 60Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.