RENNtech M178 Engine 4.0L V8 BiTurbo ECU Upgrade (601HP/605LB-FT)

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  • $3,495.00

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 M178 engine up to +115 HP and +147 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 M178 is 601 HP and 605 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 M178.
  • 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.


Performance Numbers Overview 


M178 | 4.0L V8 BiTurbo Stock Performance (at crank):

  • Rated by Mercedes-Benz:      456 HP @ 6,000rpm; 443 LB-FT @ 1,600-5,000rpm
  • Rated by RENNtech:               486 HP @ 6,250rpm; 458 LB-FT @ 3,850-5,400rpm
    • Note: Mercedes M178 engine performance when measured, obtains higher power numbers than rated from factory.


M178 | 4.0L V8 BiTurbo Modified Performance (at crank):

  • Rated by RENNtech:               601 HP @ 6,100rpm; 605 LB-FT @ 3,250rpm

                                                            529 whp @ 6,100rpm; 533 wtq @ 3,250rpm

    • Crank Performance Numbers are calculated with a 12% Drivetrain loss on the M178.