RENNtech Intermediate ECU Upgrade for E 550 BiTurbo | C207 | 480HP/523 LB-FT | M278 Engine | MY2014-2017RENNtech Intermediate ECU Upgrade for 207 E 550 BiTurbo 2014 2017 FaceLift. Up to 480HP and 523 LB FT. Gains: +78HP & +80 LB 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