RENNtech Intermediate ECU Upgrade | X166 | GL63 AMG | SUV | 638 HP / 695 LB-FT | M157 | 5.5L V8 BiTurbo | MY2013-15 mercedes-benz-gls-class--167---2020-present--gls-63-amg-esr1798052 7L V8 BiTurbo Stock Performance:

7L V8 BiTurbo Stock Performance:

Kit Specifications:

in order to create a smooth and high gloss finish

Please Note: SLS rear diffuser will partially obscure rear backup camera

RENNtech Intermediate ECU Upgrade | X166 | GL63 AMG | SUV | 638 HP / 695 LB-FT | M157 | 5.5L V8 BiTurbo | MY2013-15 mercedes-benz-gls-class--167---2020-present--gls-63-amg-esr1798052 7L V8 BiTurbo Stock Performance:Intermediate ECU Upgrade Up to 638HP 695LB FT Gains: +64HP & +72LB FT RENNtech M157 Biturbo ECU+ Upgrades are TV approved! Our proprietary ECU+ upgrade for the Mercedes M157 Biturbo 4 MATIC engine offers huge gains in performance across the entire RPM range without sacrificing around town comfort or daily driver reliability. Our intermediate level ECU upgrade offers huge gains in performance across the entire RPM range without sacrificing around town