Published on May 27th, 2020 | by Daniel Sherman Fernandez0
Mercedes-Benz New 4-cylinder engine with 48-volt system
Mercedes-Benz has just released details of a brand new engine range that electrifies diesel and petrol engines with a 48-volt network and starter generator. This new engine range will get their first showing at the 2021 E-Class premiere.
PRESS RELEASE: The two new four-cylinder OM 654 M (diesel) and M 254 (petrol) engines will be equipped for the first time with a 48-volt electrical system and an integrated starter generator. This increases the maximum power by 15 kW and the maximum torque by 180 (petrol) and 200 (diesel) Newton meters.
With the integrated starter generator (ISG), Mercedes was the first car manufacturer to use this new technology way back in 2017. The name, ISG, is an electric machine that can work both as a “drive” (engine start and partial support) and as a “power generator” (generator). The purpose of this technology, which is also known as a mild hybrid system is to increase drive comfort and save fuel which is concern as petroleum prices start to rise.
Thanks to the 48-volt electrical system used, the ISG can start the combustion engine much faster and more gently than a conventional 12-volt starter could. At the same time, the ISG is used to generate energy in push mode and can also support the combustion engine with its torque when power is high, Mercedes calls this “EQ Boost“.
OM 654 and M 254 have a new generation of the ISG, which is integrated in the Mercedes-Benz 9G Tronic automatic transmission. The electric motor, power electronics and gearbox cooler were installed directly on the gearbox in order to reduce the weight of the necessary components (no cables) and to increase efficiency. The engines are modular, hence the name “FAME” (Family of Modular Engines). They are also suitable for use in plug-in hybrid environments.
NEW M 254 four-cylinder petrol engine
This M 254 four-cylinder petrol engine is a completely new development. The two-liter machine is the successor to the M 274 and produces up to 272hp, the maximum torque is 400 Nm. A special feature of the engine is the newly developed segment turbocharger, and thanks to the 48-volt network, it can also rely on an additional electric compressor that is responsible for quickly building up the boost pressure at low engine speeds. An overboost function allows the maximum power to be increased by a further 41hp for up to 30 seconds when there is a high power requirement.
With the OM 654 M, Mercedes claims to be the world’s first diesel engine with an integrated starter generator. The revised two-liter turbo-diesel four-cylinder was given a new crankshaft for electrification, which increases the displacement by 43 to 1,993 cubic centimeters. At the same time, the injection pressure has been increased from 2,500 to 2,700 bar. The maximum power is now at 265hp, the maximum torque at 550 Newton meters. On the exhaust side, a NOX storage catalytic converter, particle filter and two SCR catalysts were added.
AMG version with ISG six-cylinder
For this new E-Class range, the in-line six-cylinder M256 with ISG is also used for the first time in this model family. In the Mercedes-AMG E 53 4MATIC + models, the engine develops a high 435hp and provides a maximum torque of 520 Newton meters. The starter generator briefly delivers an additional 16 kW of power and 250 Nm of torque.