Mercedes-Benz presenting latest 9G-Tronic in C and E-Class plug-in diesel hybrids

By JAY WONG | 6 March 2018


GENEVA:  Mercedes-Benz will debut two new pre-production models during the Geneva Motor Show that will feature its latest nine-speed 9G-TRONIC hybrid transmission in the C- and E-Class plug-in diesel hybrid variants.

Much like the S 560 e, the C- and E-Class plug-in diesel hybrids will in future use its third-generation hybrid technology with deliveries expected to begin within a few short months.

Also new is an intelligent, connected variant of the Mercedes‑Benz wall-box that will make for easier charging while offering a series of additional functions via a new app.

Plug-in hybrids represent a key technology on the road to a locally emission-free future for the motor vehicle by offering owners the benefits of two worlds, where in town they can run in all-electric mode and while on long journeys they can utilise an efficient long-range combustion engine.

The German automaker will for the first time combine its four-cylinder diesel engine with its third-generation hybrid drive to achieve higher efficiency, better ride comfort and dynamic performance as well as an impressive range.

The company is now opting for this powertrain to be fitted from its C-Class and upwards.

A key advantage in the strategic hybrid initiative is offered by the carmaker's intelligent, modular hybrid concept that's designed to be scalable and can be transferred to a large number of rear-wheel drive model series and body styles as well as left- and right-hand drive variants.

EQ Power: Vorserie des Plug-in-Dieselhybrids ist gestartet: Nächster Meilenstein bei der Elektrifizierung: Plug-in-Hybride mit Diesel-Technik kommen EQ Power: launch of preproduction of plug-in diesel hybrid: Next milestone in electrification: plug-in hybrids with diesel technology are coming
Powering the cars will be the OM 654 four-cylinder diesel engine mated to the latest-generation nine-speed 9G-TRONIC hybrid transmission with a 90kW electric output, an added electric torque of 440Nm and an electric range of around 50km.

There will be a 13.5kWh lithium-nickel-manganese-cobalt (Li-NMC) made it possible for the cell capacity to be increased from 22 to a 37 amp-hour (Ah) battery to power the electric motor which can double as an on-board charger with a charging rate from 3.6 to 7.2kW.

A discharged battery can be fully recharged in two hours via a wallbox or seven hours from the convenience of one's own home via a conventional domestic power socket.

The third-generation hybrid technology supports the driver with further improved, intelligent drive management. Through the extended use of data from the navigation system and information from the camera and the radar sensor, third-generation hybrid vehicles can look ahead, well beyond the driver's field of vision, and adjust to the specific speed/route profile.

Events such as negotiating towns on the way to the destination are taken into account when planning the available electrical energy, and during recuperation and thermal conditioning of the drive components.

In addition to a superlative driving experience with a total torque of 700Nm, available from as low as 1,400rpm, the new plug-in diesel hybrids will offer added comfort.

The high-voltage on-board electrical system supplies not only the powertrain components, but also the electric refrigerant compressor and the high-voltage heater booster.

Both allow pre-entry climate control of the interior not only in summer, but also in winter.

Also the S 560 e has an all-electric range of around 50km and its hybrid drive system combines its 270kW (367 hp) of electric power with a V6 petrol engine with an electric power output of 90kW.

The same OM 654 four-cylinder diesel aluminium engine will be utilised with a stepped-bowl combustion process – named after the shape of the combustion bowl in the piston, and includes NANOSLIDE coating for the cylinder walls.

EQ Power: Vorserie des Plug-in-Dieselhybrids ist gestartet: Nächster Meilenstein bei der Elektrifizierung: Plug-in-Hybride mit Diesel-Technik kommen EQ Power: launch of preproduction of plug-in diesel hybrid: Next milestone in electrification: plug-in hybrids with diesel technology are coming
The internal friction has been reduced by around 25%. The new engine also benefits from the use of fourth-generation common-rail injection with pressures of up to 2,050 bar.

On top of this, the engine is also more compact than its predecessor. All components relevant for efficient emissions reduction are installed directly on the engine. Thanks to the near-engine configuration, exhaust after-treatment has a low heat loss and excellent operating conditions.

Both clutch and electric motor are housed in the hybrid drive unit and the compact design was achieved by integrating and connecting the separating clutch, torsional vibration damper and torque converter lockup clutch within the rotor of the electric motor.

The torque converter with its powerful and highly efficient hydraulic circuit offers the customary smoothness when pulling away in hybrid mode.

Developed together with Bosch as part of the EM-motive joint venture, the electric motor was specially designed for the 9G-TRONIC plug-in hybrid transmission. The equally new power electronics have allowed further increases in output and torque compared with the second generation.

The electric performance of 90kW and 440Nm has helped raise the vehicle's electric mode top speed from 130 to 140kph.

Keywords