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RENNtech Power Module | 450 / 43 -Series | 417 HP / 442 LB-FT | M256 | 3.0 Inline 6 cylinder EQ Boost

RENNtech Power Module | M256 | 3.0 Inline 6 cylinder EQ Boost | ECU+ Upgrade | Up to 417 HP / 442 LB-FT | Gains: +50 HP & +74 LB-FT
SKU: 54.256.RPM.450
Renntech Piggyback ECU Tuner Renntech Piggyback ECU Tuner
Retail price without tax: $2,780.00
Renntech Piggyback ECU Tuner
Renntech Piggyback ECU Tuner
Renntech Piggyback ECU Tuner

The RENNtech Power Module (RPM) ECU tune delivers significant horsepower and torque gains across the entire power band. By modifying ignition timing and throttle mapping, optimizing air-to-fuel ratios, and modifying boost mapping for turbo-chargers the Mercedes-Benz M256 3.0 Inline 6 cylinder EQ Boost -engine gains up to +50 HP and + 74 LB-FT, based on Dyno measured power figures.

The RENNtech Power Module is contained in a CNC machined 6061 aluminum enclosure with pre-labeled wires and connectors. The RPM module comes with a bypass that can be installed in place of the module to quickly turn the vehicle back to stock performance. The harness can be uninstalled to return the vehicle to stock completely. Through our 30+ years of ECU tuning experience, countless hours of in-house research, development and long-term testing ensure that our ECU upgrade offers the best in quality, performance and reliability.


Stock: 367 HP and 368 TQ
RPM Tuned: 417 HP and 442 TQ

The RENNtech Power Module for Mercedes-Benz M256 3.0 Inline 6 cylinder EQ Boost -engines:

  • E 450 (W213 / S213 -chassis)
  • CLS 450 (C257 -chassis)
  • GT 43 AMG (X290 -chassis)
  • GLE 450 (V167 -chassis)
  • GLS 450 (X167-chassis)

Professional installation is recommended. 

  • Buyer Beware: There have been reported failiures the stock Turbo’s in the Mercedes-Benz M256 -engine. Increasing the power output without upgrading the OEM turbo charger may increase the chance of Turbo -failure. 



Contact us

7825 SW Ellipse Way, Stuart, FL 34997
(+1) 561 - 845 7888
Mon - Fri 9am - 6pm


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7825 SW Ellipse Way - Stuart, FL 34997
TEL: 561.845.7888 FAX: 561.845.6777 E-MAIL: