RENNtech ECU Upgrade | W222 | S 550 | 500HP / 625LB-FT | 4.7L V8 BiTurbo | M278 | MY2014-2017 mercedes-benz-slr-mclaren-slr-mclaren-722--2006-2011--esr6133838 To return the car back

To return the car back to stock PRE-SAFE settings turn the switch over to STOCK and plug it back into OBD2 port

0L Engine) Stock Performance:

up to + 10 HP

CLASS R (W 251) 500 4-matic [2 Filters Required] (HP: 306 | Year: 05 > 07)

With the proprietary RENNtech ECU Tuning the C292 - GLE 43 AMG Coupe gains up to +25 HP and +42 LB-FT

RENNtech ECU Upgrade | W222 | S 550 | 500HP / 625LB-FT | 4.7L V8 BiTurbo | M278 | MY2014-2017 mercedes-benz-slr-mclaren-slr-mclaren-722--2006-2011--esr6133838 To return the car backECU Upgrade 500HP 625LB FT Gains: +26HP +59LB FT Our intermediate level ECU upgrade for the Mercedes M278 engine still offers huge gains in performance across the entire RPM range, but with a slightly reduced peak HP and torque from our standard tune. This is ideal for customers who want increased performance in their daily driver without worry of extra strain on driveline components or for areas and countries with extreme altitudes, temperatures or