Glossary: Key specialist terms

Key specialist terms

48-volt on-board power supply: offers four times the power of its 12-volt predecessor system at identical currents and makes fuel savings possible. The low-voltage system does not require the additional safety architecture of a high-voltage grid.

Fuel cell: special galvanic cell that generates electricity from the chemical reaction between hydrogen and oxygen. A fuel cell consists of electrodes separated by a membrane or electrolyte (ion conductor).

CCS standard (Combined Charging System): European charging standard for electric and hybrid vehicles, described in part 3 of the IEC 62196 (DIN EN 62196). The CCS standard enables public charging at much higher capacity than today.

Efficiency label: The Energy Consumption Labelling Directive for passenger cars (Pkw-EnVKV) requires every new car to carry such a label since December 2011. The CO2 efficiency classes are assigned in dependence of the vehicle weight. To this end, the legislators have defined a reference value of the CO2 emissions for each vehicle weight. The heavier the car, the higher the reference value. Determining the efficiency class requires comparing the actual CO2 emissions with the reference value. If the CO2 emissions are exactly identical to the reference value, the car is assigned efficiency class E. Efficiency classes A+ to D are assigned to cars emitting less CO2 than the reference value. Vehicles, whose CO2 emissions are clearly higher than the reference value, are assigned efficiency classes F or G. 

"ENERGY SPACE": Thanks to this modular "ENERGY SPACE" concept, the B-Class was designed for versions with alternative powertrain from the start: Various interface points in the body shell make it possible to modify the main floor for the versions with alternative powertrain and to exploit use of a partial double floor beneath the rear bench seat. This underbody houses one large and two smaller natural gas tanks (B 200 c) or the lithium-ion battery (B 250 e). Due to this intelligent packaging method, the five-seat model retains the generously sized luggage compartment it is known for.

Inductive charging:wireless charging. The process involves the contactless transfer of energy via a time-variable magnetic field. At the heart of the technology are two coils. One is located in the parking space or the garage, a second on the underbody of the car.

Integrated starter generator (ISG): functions of starter motor and alternator combined in one electric machine. Contrary to àRSGs, these starter generators are not driven by a belt, but directly by the crankshaft. They are positioned between engine and transmission. Furthermore, ISGs enable hybrid functions such as boost, energy recovery and start/stop.

Intelligent powertrain management: The intelligent operating strategy for hybrid vehicles anticipates the course of the road and the traffic situation for maximum efficiency. This includes radar-based energy recovery, an anticipatory shifting and operating strategy, a route-based operating strategy and ECO Assist.

Lithium-ion battery: electrochemical, rechargeable voltage supply based on lithium. The advantages of lithium-ion batteries are their high energy density at a relatively low weight, their immunity to the so-called memory effect, and the low self-discharge.

Lithium-sulphur battery: potential next technology replacing lithium-ion batteries that uses sulphur as the cathode material.

Multi-way exhaust gas recirculation (EGR): a combination of low-pressure EGR (the exhaust gas is extracted downstream of the exhaust gas aftertreatment and is introduced upstream of the turbocharger) and high-pressure EGR (the exhaust gas is extracted upstream of the turbine of the turbocharger and the exhaust gas aftertreatment; it is introduced downstream of the intercooler and the throttle valve). By adding exhaust gases, the oxygen concentration of the mixture is reduced. Due to the lower oxygen concentration, less fuel is injected to combust it all completely. The calorific value or energy content of the mixture is reduced and consequently also the reaction rate and the combustion temperature - this reduces the formation of nitrogen oxide. Cooling the recirculated exhaust gas amplifies this effect. At all operating points, this reduces the formation of both nitrogen oxide and particulates even before the exhaust gas undergoes treatment.

NANOSLIDE®: Innovative and economical process for reducing fuel consumption and CO2 emissions in an internal combustion engine. An extremely thin, low-friction coating is applied to the inner surfaces of the cylinders in aluminium crankcases. As up to 25 percent of the energy in fuel is used to overcome in-engine friction under partial load, fuel savings of several percent are achievable with NANOSLIDE®.

9G-TRONIC plug-in hybrid transmission: The third-generation hybrid transmission evolved on the basis of the 9G-TRONIC PLUS automatic transmission. The torque converter, clutch and electric motor are housed in the innovative hybrid drive unit. The remarkably compact design was achieved by integrating and connecting the separating clutch, torsional vibration damper and torque converter lock-up clutch within the rotor of the electric motor.

Plug-in fuel cell powertrain: Innovative powertrain concept of the GLC F-CELL combining the advantages of both zero-emission technologies. Due to its intelligent operating strategy for using the two energy sources, it always adapts optimally to the particular operating situation.   At the same time, the combination accounts for the gradual expansion of the hydrogen filling station infrastructure in an ideal manner.

Energy recovery: The generator converts kinetic energy into electrical energy, for example during braking or in overrun mode. The recovered energy flows back into the battery and is available for future acceleration manoeuvres.

Belt-driven starter generator (RSG): Combination of starter motor and generator, which like conventional alternators is connected to the engine's crank gear via a drive belt system.

Offset: Offset between the longitudinal axis of the crankshaft and the centre axis of the cylinders. This offset has two advantages: the piston lateral force at the instant of ignition is reduced and the crankcase can be of more compact design.

2nd-Used-battery storage system: stationary energy storage systems made of used batteries from electric and hybrid cars. This efficient dual use improves the LCA and the life-cycle costs of electromobility.

Stack: To achieve higher voltages, several fuel cells are connected in series to create a stack.

Stepped-bowl combustion process: A characteristic feature of the pistons of a direct-injection diesel engine is a recess (bowl) in the piston crown in which the injected fuel is swirled and mixed with the air. The stepped-bowl design (instead of having the conventional omega shape) has a number of advantages such as excellent air utilisation with low particulate emissions and higher efficiency thanks to a higher combustion rate. The changed flow conditions in the combustion chamber result in reduced heat loss through the cylinder walls as well as in a more uniform temperature distribution at the cylinder head and reduced load on the highly stressed valve saddles. The overall result is reduced wall heat loss, which likewise contributes to increased efficiency.

Wallbox charging station: personal charging station for home or place of work. The wallbox charging station in Mercedes-Benz design impresses with an AC charging capacity of up to 22 kW (depending on vehicle), and can be installed indoors or outdoors. Different variants of the Mercedes-Benz Wallbox are available from Mercedes-Benz dealers, and can be purchased there together with an installation voucher.