Mercedes AMG GT-R (2018on) – RENNtech ECU Hand Held Tuner





RENNtech HHT (hand held tuner) allows you the unlimited ability to switch between tuned and stock ECU programming and requires no ECU removal!

Their 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 has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980s! Their experience, countless hours of in-house research, development and exhaustive testing ensure that Their proprietary ECU upgrade offers incredible performance gains and rock solid daily driver reliability.

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


With the proprietary RENNtech ECU Tuning the C190 AMG GT R gains up to +50 HP and +73 LB-FT, based on power numbers measured by RENNtech. Please note that the Mercedes M178 engine performance when measured, obtains higher numbers than rated from factory. The maximum power number reached with the RENNtech ECU Upgrade for the AMG GT R is 659 HP and 614 LB-FT.




  • We have found the M178 engine stock performance numbers vary from the baseline figures claimed by Mercedes Benz. We typically see higher baseline numbers than claimed by the factory.
  • Power gains are calculated based on stock numbers measured by RENNtech. Crank Performance Numbers are calculated with a 12% Drivetrain loss on the AMG GT.


Performance Numbers Overview

AMG GT R (MY2018+ | C190 | M178 | 4.0L V8 BiTurbo) Stock Performance (at crank):

  • Rated by Mercedes-Benz:      577 HP @ 6,250rpm; 516 LB-FT @ 1,900-5,000rpm
  • Rated by RENNtech:               609 HP @ 6,500rpm; 541 LB-FT @ 3,950rpm
    • Note: Mercedes M178 engine performance when measured, obtains higher power numbers than rated from factory.



    AMG GT R (C190 | M178 | 4.0L V8 BiTurbo) Modified Performance (at crank):

    • Rated by RENNtech:              659 HP @ 6,150rpm; 614 LB-FT @ 4,450rpm
    •                                                     580 whp @ 6,800rpm; 540 wtq @ 5,600rpm
      • Crank Performance Numbers are calculated with a 12% Drivetrain loss on the AMG GT.

Due to some of the products coming direct from RENNtech USA please allow 7-10 days for delivery

Prices may vary in accordance to the current exchange rate, please contact us for the current confirmed price

Our refunds policy can be found here