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RENNtech ECU Upgrade | SL 65 AMG | R231 | 735HP/836LB-FT | 6.0L BiTurbo V12 | M279

RENNtech ECU Upgrade for 231 - SL 65 AMG. Up to 735HP and 836LB-FT.
Gains: +114HP & +100LB-FT
SKU: ECU:54.231.SL65.FL
Retail price without tax: $3,495.00

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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.

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RENNtech has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980's! 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 vehicles entire power band. By modifying ignition timing and throttle mapping, optimizing air/ fuel ratios, increasing the engines rev limiter and modifying boost mapping for turbo charged vehicles, RENNtech performance software unleashes your Mercedes true potential.

  • Note: We have found the new M279 engine stock performance numbers vary from the baseline figures claimed by Mercedes Benz. We typically see slightly higher baseline numbers than claimed by the factory.


SL 65 (R231) Stock Performance:

  • 621 HP @ 4800 RPM; 738 LB-FT @ 2300-3000 RPM


Modified Performance:

  • 735 HP @ 5200 RPM; 836 LB-FT @ 3500 RPM



  • +114 HP & +100 TQ


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: