RENNtech ECU+ Upgrade | R231 | SL 550 | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 mercedes-benz-glk-class--204---2010-present--glk-350-blue-effiency-esr1676768 RPM Tuned: 601 HP |

RPM Tuned: 601 HP | 562 LB-FT

Includes ECU Upgrade

Rated by RENNtech:                628 HP @ 6

5L V8 BiTurbo

Gains: up to +228 HP | +182 LB-FT

RENNtech ECU+ Upgrade | R231 | SL 550 | 540HP / 705LB-FT | 4.7L V8 BiTurbo | M278 mercedes-benz-glk-class--204---2010-present--glk-350-blue-effiency-esr1676768 RPM Tuned: 601 HP |ECU+ Upgrade 540HP 705LB FT Gains: +92HP +167LB 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