Plug-in hybrids are an important milestone on the road to zero-emissions driving. Mercedes‑Benz Cars is pushing ahead with the development of its plug-in hybrids under the EQ Power label. With the A 250 e, A 250 e Saloon and B 250 e models from the compact-car family with the third-generation hybrid drive are now celebrating their premiere. The A 250 e and A 250 e Saloon can be ordered now at prices from €36,943.55 and €37,300.55. Sale of the B 250 e starts a few weeks later. Market launch of the models will take place this year. The EQ Power for the A- and B-Class underscores Mercedes-Benz’s plug-in initiative: the company aims to extend its offering to more than 20 model variants by 2020.
For the new compact vehicles with EQ Power, (electric) driving pleasure and suitability for everyday use are to the fore. This is illustrated by the models highlights:
- Electric operating ranges of 70-75 km (NEDC)
- Electric output 75 kW
- System output 160 kW
- System torque 450 Nm
- Top speed 140 km/h (electric)/235 km/h (total; A-Class Compact Saloon)
- Acceleration 0-100 km/h in 6.6 seconds (A-Class Compact Saloon)
- Hardly any restrictions on the load compartment
The vehicles belonging to Mercedes-Benz’s compact car family feature transversely mounted engines. A compact hybrid traction head has been developed for the 8F-DCT dual clutch transmission which follows the same technical principles as the corresponding component on the vehicles with a longitudinally installed engine. It is a permanently excited synchronous machine as an internal rotor. The stator is permanently integrated in the traction head housing, while the low-loss wet clutch is incorporated in the electric machine’s rotor. On-demand stator and rotor cooling allow use of the electric motor’s peak and continuous output without any problems.
For the first time on a Mercedes-Benz vehicle, the combustion engine is started by the electric motor – the compact hybrids do not have a separate 12-volt starter.
High system output provides for plenty of driving enjoyment
The electric machine achieves 75 kW. Together with the 1.33-litre four-cylinder engine this adds up to a system output of 160 kW (218 hp) and a system torque of 450 Nm. Thanks to the EQ Power of the electric machine the A 250 e and B 250 e react immediately to a step on the accelerator, and the performance is impressive: the A 250 e, for example, requires 6.6 seconds for the sprint from 0 to 100 km/h, and its top speed is 235 km/h (see next page for further data).
A lithium-ion high-voltage battery with a total capacity of approx. 15.6 kWh is used as an electric energy storage unit. It can be charged at an external electric energy source. The A 250 e and B 250 e can be charged with alternating or direct current. A corresponding vehicle socket is located in the right-hand side wall of the vehicles. This means that the compact plug-in hybrids can be charged at a 7.4 kW Wallbox with alternating current (AC) within 1 h 45 min from 10-100 percent SoC (Status of Charge). For direct-current charging (DC) the battery can be charged from 10 – 80 percent SoC in around 25 minutes.
The batteries are supplied by the wholly owned Daimler subsidiary Deutsche ACCUMOTIVE. The high-voltage battery is water-cooled and weighs approx. 150 kg.
An innovative exhaust system enables ingenious packaging: rather than extending to the end of the vehicle, the exhaust ends in a centrally positioned outlet under the vehicle floor, with the rear silencer housed in the transmission tunnel. Integrating the fuel tank into the axle installation space creates room beneath the rear seats for the high-voltage battery. This results in only minimal reduction in boot capacity for the A 250 e and B 250 e compared to the sister models without hybrid engines.
Because the compact vehicles use third-generation plug-in technology, all of their functions are also available. These include in particular the intelligent, route-based operating strategy, taking factors such as navigation data, speed regulations and route into account. The operating strategy takes into account the entire planned route and prioritises the electric driving mode for the most sensible route sections in each case.
With the launch of MBUX (Mercedes-Benz User Experience) the previous plug-in operating modes of all EQ Power models have been converted to drive programs. That means that in every Mercedes-Benz plug-in hybrid the new drive programs “Electric” and “Battery Level” are available. This is the case from the outset for the compact models. Maximum e-performance can be experienced in “Electric”. The combustion engine is only engaged if the driver uses kickdown on the accelerator pedal. In the “Electric” program the recuperation strength can also be selected via paddles behind the steering wheel. The paddles on the steering wheel enable the selection of five different recuperation levels (DAUTO, D+, D, D– and D—).
Comfort, ECO and Sport modes are also available. According to the given requirements, the driver is thus able to give priority to electric driving, place the emphasis on driving dynamics in combined drive mode or give preference to combustion mode in order to save electric range, for example.
A key comfort feature is pre-entry climate control before the vehicle is started, because the A 250 e and B 250 e have an electric refrigerant compressor. The pre-entry climate control can also be activated conveniently by smartphone. The trailer load of the compact hybrids is impressive at 1600 kg (braked).
Mercedes me Charge helps with charging en route
As well as using the domestic power supply, e.g. at a Mercedes-Benz Wallbox, convenient and uncomplicated charging is possible during the journey, too. That’s because the MBUX infotainment system (Mercedes-Benz User Experience) assists the driver in finding charging stations. The MBUX system understands natural speech, allowing the driver to start a search simply by saying “Hey Mercedes, find charging stations nearby”.
Via Mercedes me Charge, drivers of a plug-in hybrid model can optionally obtain access to one of the world’s largest charging networks, with over 300 different operators in Europe alone (municipalities, car parks, motorways, shopping centres, etc.). Thanks to navigation, Mercedes-Benz customers can find these stations easily and can gain convenient access to the charging stations via the Mercedes me Charge card, the Mercedes me App or directly from the car. No separate contracts are necessary for this: apart from simple authentication, customers benefit from an integrated payment function with simple billing after they have registered their payment method once. Each charging procedure is booked automatically. The individual charging processes are clearly listed in a monthly invoice.
The Mercedes-Benz plug-in strategy
Plug-in hybrids offer customers the best of both worlds: in town they run in all-electric mode, while on long journeys they benefit from the range of the combustion engine. They make the vehicle more efficient overall because they can firstly recover energy during braking and secondly allow the combustion engine to run in favourable operating ranges. EQ Power also provides for highly dynamic performance. EQ Power+ stands for the high-performance hybrid technology which Mercedes‑AMG is already applying with success in Formula 1 and which it will be deploying on the road in future.
By the end of 2019 Mercedes-Benz will have more than ten plug-in hybrids in the range – an attractive portfolio from the compact car to the flagship Mercedes-Benz S-Class. The aim is to be able to offer customers well over 20 model variants in 2020.
The new plug-in hybrids of the S-, E- and C-Class with electric ranges of up to 50 km in accordance with NEDC were unveiled last year. In the C- and E-Class, Mercedes-Benz is the only manufacturer to combine the diesel engine with plug-in technology, offering this set-up in the Saloon and Estate versions of these two model series. The update of the GLC with EQ Power is already in the starting blocks. Also equipped with the third-generation hybrid drivetrain, it provides the point of entry to the SUV segment. The next member of the EQ Power family will be the GLE – with a planned range of around 100 km, it points the way to an even more powerful electric driving experience.
Source: Daimler AG