The Mercedes GLS 500 (4.7 V8 TT) 455hp (2015 - 2018) produces 455bhp and 700Nm in standard form. Our Stage 1 ECU tuning file raises output to 500bhp and 850Nm, a gain of 45bhp and 150Nm, with no hardware modifications required. The file is delivered through the ByteFLASH portal and is ready to write to the vehicle.