Mercedes CLS63 AMG Biturbo (2011-2014) – RENNtech ECU upgrade





RENNtech has been at the forefront of ECU tuning since electronic engine management started to show up in vehicles during the mid 1980’s! Their experience, countless hours of in house research, development and exhaustive testing ensure that their 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.


CLS 63 (C218) Stock Performance (Without Performance Package):

  • 518 HP @ 5500 RPM; 516 LB-FT @ 4800 RPM

Modified Performance (Without Performance Package):

  • 669 HP @ 5500 RPM; 734 LB-FT @ 3800 RPM


CLS 63 (C218) Stock Performance (With Performance Package):

  • 550 HP @ 5500 RPM; 590 LB-FT @ 4800 RPM

Modified Performance (With Performance Package):

  • 669 HP @ 5500 RPM; 734 LB-FT @ 3800 RPM
*NOTE – We would need either the ECU or the vehicle bringing to our premises in Cheshire

Due to some of the products coming direct from RENNtech USA please allow 7-10 days for delivery

Prices may vary in accordance to the current exchange rate, please contact us for the current confirmed price

Our refunds policy can be found here