RENNtech Intermediate ECU Upgrade – S 550 Coupé BiTurbo 4MATIC (C217 – 480HP/523TQ – M278 Engine)


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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 fuel quality concerns.

Our intermediate ECU tune increases performance from 429 HP and 516 lb/ft torque to 470 HP and 513 lb/ft at the crank! This is a slight reduction from our standard tune but still offers white knuckle performance at one of the most affordable price points in the tuning market.


S 550 Coupé (C217- M278 Biturbo Engine) Stock Performance:

429 HP @ 5,250 RPM

516 LB-FT @ 1,800 RPM

Note: Mercedes M278 engine performance when measured obtains higher numbers that rated from factory. 


Modified Performance:

480 HP @ 4900 RPM

523 LB-FT @ 4100 RPM

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