RENNtech ECU+ Upgrade | R231 | SL 63 AMG | 669 HP / 734 LB-FT | M157 | 5.5L V8 BiTurbo | MY2015+

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 be reflashed at any time as many times as you wish.

RENNtech M157 Biturbo ECU+ Upgrades are TÜV approved!

Our proprietary ECU+ upgrade for the Mercedes M157 engine offers huge gains in performance across the entire RPM range without sacrificing around town comfort or daily driver reliability.

Our ECU tune offers the biggest performance gains on the market; increasing performance from 563 HP and 594 lb/ft torque, to an astonishing 669 HP and 734 lb/ft at the crank!