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RENNtech ECU+ Upgrade | C238 | E400 4MATIC | 392 HP/432 LB-FT | 3.0L V6 BiTurbo | M276

ECU+ Upgrade | Up to 392 HP / 463 LB-FT | Gains: +53 HP & +78 LB-FT
SKU: ECU:54.238.E400BT
Retail price without tax: $2,240.00

RENNtech M276 Biturbo ECU Upgrades are TÜV approved!

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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.

Our proprietary ECU upgrade for the Mercedes M276 engine offers huge gains in performance across the entire RPM range without sacrificing around town comfort or daily driver reliability.

Our ECU tune offers the biggest performance gains on the market with our dyno results increasing performance from 329 HP and 354 lb/ft torque, up to an astonishing 392 HP and 432 lb/ft at the crank!


With the proprietary RENNtech ECU Tuning the W213 - E400 gains up to +53 HP and +78 LB-FT, based on power numbers measured by RENNtech. Please note that the Mercedes M276 engine performance when measured, obtains higher numbers than rated from factory. The maximum power number reached with the RENNtech ECU Upgrade for the E400 is 392 HP and 463 LB-FT.



  • 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 17% Drivetrain loss on 4MATIC vehicles.
  • Numbers published by MBUSA are an average over a 750rpm range for HP and a 2,400rpm 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. Please call for details and Race fuel options +1-561-845-7888.


Performance Numbers Overview 

E400 (MY2018+ | C238 | M276 | 3.0L V6 BiTurbo) Stock Performance (at crank):

  • Rated by Mercedes-Benz (avg.):                               329 HP @ 5,250-6,000rpm; 354 LB-FT @ 1,600-4,000rpm
  • Dyno measured by RENNtech (peak @crank):          339 HP @ 5,600rpm; 385 LB-FT @ 3,030rpm

E400 (MY2018+ | C238 | M276 | 3.0L V6 BiTurbo) Modified Performance (at crank):

  • Rated by RENNtech (peak @crank):              392 HP @ 5,800rpm; 463 LB-FT @ 3,550rpm
  • Rated by RENNtech (peak @wheel):              325 whp @ 5,800rpm; 384 wtq @ 3,550rpm
    • Crank Performance Numbers are calculated with a 17% Drivetrain loss on 4MATIC vehicles.

For detailed explanation on crank HP, wheel HP, drivetrain loss, etc. please click here.


Dyno-Graph for Performance measured at the wheels:


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: