RENNtech ECU Upgrade for C 350 | W203 | 290 HP / 278 LB-FT | MY2006-2007 mercedes-benz-s-class--222---2018-2020--s-65-amg-esr3393684 The RENNtech transmission upgrade is

The RENNtech transmission upgrade is complete transmission software upgrade and has to be done at the RENNtech HQ in Stuart

CLASS E (W 212) 550 4-matic [2 Filters Required] (HP: 408 | Year: 11 > )

CLASS S LONG (W 221) 351 V6 4-Matic Blue Efficiency (HP: 306 | Year: 11 > )

Thanks to the dual-mode exhaust flap system

and RSQ8 gains up to +80 HP and 144 LB-FT

RENNtech ECU Upgrade for C 350 | W203 | 290 HP / 278 LB-FT | MY2006-2007 mercedes-benz-s-class--222---2018-2020--s-65-amg-esr3393684 The RENNtech transmission upgrade isRENNtech ECU Upgrade for 203 C 350, up to 290HP, 278LB FT. Gains: +22HP & 20LB FT 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