RENNtech ECU+ Upgrade | C190 | AMG GT Black Series | 843 HP / 739 LB-FT | 4.0L V8 BiTurbo | M178





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 has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980s! Our experience, countless hours of in-house research, development and exhaustive testing ensure that our 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 Black Series gains up to +99 HP and +95 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 Black Series is 843 HP and 739 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.
  • Our numbers will be dependent on conditions and fuel quality. 93+ Octane gasoline is mandatory with this Performance Upgrade.
  • States known for poor fuel quality have to be supplied with a lower power setup. Please call for details and Race fuel options +1-561-845-7888.

This is a Special-order part and requires your vehicles VIN/Chassis Number

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

Performance Numbers Overview


AMG GT Black Series (MY2021) | C190 | M178 | 4.0L V8 BiTurbo) Stock Performance (at crank):

  • Rated by Mercedes-Benz:      720 HP @ 6,700 rpm; 590 LB-FT @ 2,000 rpm
  • Rated by RENNtech:               744 HP @ 6,850 rpm; 644 LB-FT @ 3,700 rpm
  • Note: Mercedes M178 engine performance when measured, obtains higher power numbers than rated from factory.



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

  • Rated by RENNtech:         843 HP @ 6,300rpm; 739  TQ @ 5,400rpm
  •                                            742 whp @ 6,300rpm; 650 wtq @ 5,400rpm
  • Crank Performance Numbers are calculated with a 12% Drivetrain loss on the AMG GT.

Our refunds policy can be found here