With the newest update of their Software Upgrade for the M278 – 4.7L V8 BiTurbo, RENNtech boosts the 550-Series to AMG Power Levels.

The RENNtech upgraded M278 now produces 540 HP and 705 LB-FT at crank. Compared to power numbers by Mercedes-Benz, the 550 gains up to 138 HP and 262 LB-FT. This Software update delivers up to 10 HP and 99 LB-FT more than the previous version.

The vast amount of increased torque across the entire RPM range gives the 550 an extra edge to compete with AMG powered vehicles. All this without sacrificing around town comfort and daily driver reliability.

The M278 – 550 engine is currently offered for the W222 – S Class, C217 – S Coupι/Cabriolet, C207 – E Coupι/Cabriolet, C218 – CLS Class, X166 – GLS SUV and R231 – SL Class.

The updated RENNtech software will also be shipped for the discontinued models, the W221 – S Class, W212 – E Class, C216 – CL Class, W166 – ML Class and X166 – GL Class.

In addition to the updated ECU Upgrade, RENNtech is releasing the all new ‘RENNtech 550 Sport Package’. Included in this all-around transformation package are ECU-Upgrade, Carbon-Fiber Decklid Spoiler and Stainless Steel Sport Mufflers. Optional are your choice of RENNtech Deep Monolite Wheels in Brushed Aluminum or Gunmetal. Currently available for select models.


550 – M278 | 4.7L V8 BiTurbo Stock Performance:
*W212-E, C207-E, C218-CLS
Rated by Mercedes-Benz: 402 HP @ 5,000-5,750 RPM | 443 LB-FT @ 1,600-4,750 RPM
Rated by RENNtech: 435 HP @ 5,050 RPM | 508 LB-FT @ 2,350-3,650 RPM

*W222-S, C217-S, R231-SL, C216-CL
Rated by Mercedes-Benz: 449 HP @ 5,250-5,550 RPM | 516 LB-FT @ 1,800-3,500 RPM
Rated by RENNtech: 469 HP @ 5,050 RPM | 563 LB-FT @ 2,350-3,650 RPM


550 – M278 | 4.7L V8 BiTurbo RENNtech Upgraded Performance:
*Applies to all Models, crank power calculation based on 17% Drivetrain loss on 4-MATIC models and 14% Drivetrain loss on RWD models
Rated by RENNtech: 540 HP @ 5,300 RPM | 705 LB-FT @ 3,400-4,200 RPM



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