M 256 – The New Mercedes-Benz High-Performance Six-Cylinder In-Line Gasoline Engine with Intelligent 48V Electrification

Authors

Dipl.-Ing. O. Vollrath, Dipl.-Ing. J. Banken, Dipl.-Ing. P. Lautenschütz, Dr.-Ing. O. Storz, et al., Daimler AG, Stuttgart

Year

2017

Print Info

Fortschritt-Berichte VDI, Series 12, No 802

Summary

The M 256 six-cylinder gasoline engine is the first gasoline member of the new family of in-line engines from Mercedes-Benz and thus replaces its successful V-type predecessor, the M 276. Thanks to 48V electrification, which was factored into the design of the engine from the outset, and a number of other innovative measures, it has been possible, despite ambitious performance-related goals, to achieve considerable fuel savings. Hence, through the connection of a 48V integrated starter generator, an electric auxiliary charger and a powerful twinscroll turbocharger, the beltless engine delivers an excellent response across the entire engine speed range. In addition to the use of 48V components, the technology portfolio of the innovative engine comprises modules such as a variably controlled oil circuit, an intelligent heat management system and a gasoline particulate filter. Along with an almost 20% CO₂ reduction and an increase in output of over 15% compared with the previous V6 engine, the result is a six-cylinder machine with a fuel economy on a par with that of a four-cylinder engine and an output capable of competing with an eight-cylinder machine.