RennTech Performance ECU Upgrade For Mercedes-Benz C253 GLC 63 AMG, S

VENDOR: RennTech

SKU: 54.253C.GLC63BI

All orders will include an AutoTalent window decal


RENNtech HHT (hand held tuner) allows you the unlimited ability to switch between tuned and stock ECU programming and requires no ECU removal. RennTech 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. RennTech 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 intermediate RennTech ECU Tuning the C253 - GLC63 AMG 4MATIC+ gains up to +48 HP and +80LB-FT, based on power numbers measured by RennTech. Please note that the Mercedes M177 engine performance when measured, obtains higher numbers than rated from factory. The maximum power number reached with the intermediate RennTech ECU Upgrade for the GLC63 and GLC63 S AMG+ is 574 HP and 612 LB-FT.

All RennTech HSMs are adjustable via USB using either Windows or Android OS.The software allows the user to adjust the ride-height at each corner in 1mm increments independently. The software also has three locations where the user can store pre-configured suspension setups for quick changes.


RENNtech stock power numbers are measured with the GLC 63 AMG. Tune is compatible with GLC 63 AMG and GLC 63 S AMG. Maximum power numbers are for both, S and non-S models.

We have found the M177 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 16% Drivetrain loss on 4MATIC+ vehicles.

Numbers published by MBUSA are an average over a 750rpm range for HP and a 2,750rpm range for TQ. Power gains are calculated based on the peak stock performance measured by RENNtech.

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


  • Gains: +48 HP & +80 LB-FT
  • Long-lasting and driver reliability
  • Significant gains in horsepower
  • Increases the performance
  • Significant gains torque 
  • Increasing the engine's rev limiter
  • Incredible performance gains

Stock Performance:

  • 469 HP @ 5,500-6,250rpm; 479 LB-FT @ 1,750-4,500rpm
  • 526 HP @ 6,250rpm; 532 LB-FT @ 4,600rpm

Modified Performance:

  • 574 HP @ 5,750rpm; 612 LB-FT @ 3,400rpm
  • 482 whp @ 5,750rpm; 514 wtq @ 3,400rpm

      Vehicle Fitment:    

      • 2016 Mercedes-Benz C253 GLC 63 AMG
      • 2017 Mercedes-Benz C253 GLC 63 AMG
      • 2018 Mercedes-Benz C253 GLC 63 AMG
      • 2019 Mercedes-Benz C253 GLC 63 AMG
      • 2020 Mercedes-Benz C253 GLC 63 AMG
      • 2016 Mercedes-Benz C253 GLC 63 AMG S
      • 2017 Mercedes-Benz C253 GLC 63 AMG S
      • 2018 Mercedes-Benz C253 GLC 63 AMG S
      • 2019 Mercedes-Benz C253 GLC 63 AMG S
      • 2020 Mercedes-Benz C253 GLC 63 AMG S


                                Images are for representation purpose only and may differ depending on application.