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.

The RENNtech tuning software for Mercedes offers significant gains in horsepower and torque across the vehicles entire power band. By modifying ignition timing and throttle mapping, optimizing air/ fuel ratios, increasing the engines rev limiter and modifying boost mapping for turbo charged vehicles, RENNtech performance software unleashes your Mercedes true potential.