Presented by RENNtech – Introduced in 2017, the M256 -engine marked the return of the inline 6 cylinder to the Mercedes-Benz family. The 3.0 -liter engine with EQ Boost, a 48V mild-hybrid system that adds power and torque on request, is silky smooth and inherently well balanced.
Developed in two versions, the M256 can be found in the current 450 and AMG 53 line up. The 450 -version has a Dyno measured power rating of 392 hp, and the AMG 53 -version 436 hp, great numbers, numbers that RENNtech was quick to improve upon.
For the 450 -version, found in CLS, GLE, and GLS -models, RENNtech’s ECU upgrade develops an additional 60 hp and 76 lb-ft of torque, bringing the total power output up to 452 hp and 475 lb-ft. The figure is easy to remember; the 450 delivers 450 HP, and 14 hp more than the standard AMG 53 version of the engine.
For the AMG 53 version, found in the CLS, and E-class, the RENNtech ECU upgrade uncorks an additional 49 HP and 46 lb-ft of torque, boosting the total power figure up to 485 HP and 456 lb-ft. Track tested, the RENNtech tuned CLS AMG 53 is powerful and quick, running down the ¼ mile in 12.1 seconds with a trap speed of 114 mph!
The M256 engine is a sharp, technologically advanced engine with a pleasing tone of nostalgic inline 6-cylinder sound. And with the RENNtech ECU upgrade, both the 450 and AMG 53 move into a new and exhilarating territory. After all, what RENNtech does best is to improve on the great.
Presented by RENNtech
Performance without compromise. This is the foundation upon which we have built our reputation. Established in 1989 by Hartmut Feyhl, RENNtech has evolved and grown from servicing AMG’s customers into the foremost authority on tuning and customizing AMGs and Mercedes-Benz.