Fourth generation plug-in hybrid.

September 06, 2022 - In the new GLC, Mercedes-Benz already relies on the fourth generation of the plug-in hybrid drive.

Using the identical basic engines, electrification has taken another big step. With an electric drive power of up to 280 kW (381 hp) and an all-electric range of more than 100 kilometres (WLTP), the plug-in hybrid models of the GLC will in many cases and on many days be on the road purely electrically, without the use of the combustion engine. Whether with one of the two petrol engines or the diesel: as plug-ins, they are not only very efficient but also extremely dynamic on the road.

The new high-voltage system is more compact and more powerful. The number of high-voltage interfaces is significantly reduced. Integration of the power electronics into the transmission housing reduces the required installation space and simplifies assembly processes in production. In addition, a higher system voltage increases the drive power without the need for larger cable cross-sections.

High agility when moving off

The high power density of the hybrid drive unit comes courtesy of a permanently excited internal rotor synchronous motor. The 440 Nm peak torque of the electric motor is ready to go right from the start, resulting in high agility when moving off, along with dynamic driving performance. The full electric power is available up to 140 km/h.

The high-voltage battery is an in-house development by Mercedes-Benz. In particular, the total capacity of 31.2 kWh in combination with more efficient recuperation and improved aerodynamics allow an all-electric range of more than 100 kilometres. To accommodate the high power density, the high-voltage battery has an internal cooling system. The thermal management system can therefore control the operating temperature irrespective of the climate control in the vehicle interior. In addition to continuous operation in hot and cold regions, this also allows quick charging with direct current.

Even when the battery is completely discharged, it can be fully charged in around 30 minutes with the optional 60 kW DC charger. A standard-fit 11 kW charger (depending on the market) is available for three-phase charging at a Wallbox connected to the domestic AC mains. The standard charging cable can be stored within easy reach in a floor compartment just behind the tailgate.

Recuperate instead of braking

Also thanks to improved recuperation, the new GLC offers significantly higher overall efficiency of the hybrid system compared to its predecessor: The amount of recovered electrical energy has increased significantly.

Recuperation recovers electricity for the e-drive from the vehicle's kinetic energy. It is based on an interlocking interaction between the components: while the electric motor receives electrical energy during acceleration to generate mechanical energy, it is mechanically driven by the vehicle's kinetic energy on the overrun and during deceleration, thus working as a generator and generating electrical energy. This is fed into the vehicle's high-voltage battery and is available for the drive system.

A decisive factor for efficiency in recuperation is the interaction of the hydraulic service brake with the electric motor. In addition, the automatic transmission performs several gearchanges during deceleration. The use of a vacuum-independent braking system in the new GLC has significantly optimised the entire interaction. Depending on the driving situation and the driver's braking requirements, this braking system automatically controls the flexible transition between hydraulic braking and recuperation. This allows the maximum recuperation power of up to 100 kW to be achieved more frequently, and over a longer period of time. For this purpose, the system variably reduces the braking power of the hydraulic brake, even at constant pedal pressure, so that the high recuperation power is maintained as speed decreases. A further, pleasant effect for the driver is that he/she does not perceive this automatic transition.