RENNtech ECU+ Upgrade | R231 | SL 550 | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 mercedes-benz-cl-class--215---2001-2006--cl-500-esr9379736 With the proprietary RENNtech ECU

With the proprietary RENNtech ECU Tuning the W222 - S63 AMG 4MATIC+ gains up to +87 HP and +44 LB-FT

This highly integrated pre-preg carbon fiber spoiler compliments the sophisticated and refined C-Coupe exterior design language

Our proprietary tuning module stores both the RENNtech tuned file and your vehicles stock file

E 63  AMG (211) Stock Performance:

CLASS S (W 221) 500 [ONLY USA] [2 Filters Required] (HP: 387 | Year: 05 >)

RENNtech ECU+ Upgrade | R231 | SL 550 | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 mercedes-benz-cl-class--215---2001-2006--cl-500-esr9379736 With the proprietary RENNtech ECUECU+ Upgrade 540HP 705LB FT Gains: +66HP +139LB FT 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