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RENNtech ECU Upgrade GL 450 (X166- 501 HP / 576 LB-FT for M278 Biturbo)

RENNtech ECU Upgrade for 166 - GL 450 BiTurbo. Up to 501HP and 576LB-FT.
Gains: +139HP & +170LB-FT
SKU: ECU:54.166.GL450BT.V8
Retail price without tax: $2,480.00

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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 M278 engine offers huge gains in performance across the entire RPM range without sacrificing around town comfort or daily driver reliability.

Our ECU tune offers huge performance gains; increasing performance from 362 HP and 406 lb/ft torque, to an astonishing 501 HP and 576 lb/ft at the crank! This allows the M278 engine to run the quarter mile in an impressive time and dramatically improves 0-60 mph times.


GL 450 (X166- M278 Biturbo Engine) Stock Performance:

  • 362 HP @ 5,250 RPM; 406 LB-FT @ 1,800 RPM
  • Note: Mercedes M278 engine performance when measured obtains higher numbers that rated from factory.


Modified Performance:

  • 501 HP @ 4900 RPM; 576 LB-FT @ 4100 RPM



  • +139HP / +170 LB-FT


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: