RENNtech ECU Hand Held Tuner (HHT) for SLK 55 | R171 | 380 HP / 395 TQ | MY2005-2009 rpm The rear diffuser also fits

The rear diffuser also fits with the OEM exhaust tips

CLASS M (W 166) ML 350 V6 Blue Efficiency (HP: 306 | Year: 11 > )

+20HP & +14TQ

The R1 Performance Package was developed to deliver maximum power running on standard 93 octane gas

+114 HP & +100 TQ

RENNtech ECU Hand Held Tuner (HHT) for SLK 55 | R171 | 380 HP / 395 TQ | MY2005-2009 rpm The rear diffuser also fitsRENNtech ECU HHT (HandHeldTuner) for the R171 SLK 55 AMG. Up to 380HP and 395 LB FT TQ. Gains: +18HP & +17TQ. 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.