In 1999, Mercedes had dropped the production of the inline six-cylinder engines with the last M 104. Surprisingly, in 2017 the Mercedes M 256 engine brought the long-buried in-line layout back. As a successor to the Mercedes M 276 the M 256 engine debuted mid-2017 in the new S-Class (222). In its expansion stages, the 3.0-liter unit with twin-turbo charging can deliver up to 408 hp and over 500 Newton meters of torque.
An electric boost compressor from BorgWarner and an integrated start generator ensure that the turbocharger is bypassed and the power is available from the start. As a result, the time of the turbo lag is bridged during acceleration, until the exhaust gas turbocharger kicks in.
The production of the M 256 takes place at the Mercedes-Benz factory in Stuttgart-Untertürkheim.