RENNtech ECU+ Upgrade | W166 | GLE63 AMG | SUV | 669 HP / 734 LB-FT | M157 | 5.5L V8 BiTurboECU+ Upgrade Up to 669HP 734LB FT Gains: +64HP & +108LB FT RENNtech HHT (hand held tuner) allows you the unlimited ability to switch between tuned and stock ECU programming and requires no ECU removal! Our proprietary tuning module stores both the RENNtech tuned file and your vehicles stock file. The module plugs directly into the OBD2 port and delivers the file you choose directly to the ECU. Programming takes only a few minutes and the vehicle can