Above all, the Mercedes Vision EQXX is a Mercedes demonstration about the progress that aerodynamics can bring. It will be difficult to put into series production, but some of these cutting-edge solutions will be able to be used in future electric models.
With the Mercedes Vision EQXX, the Stuttgart based premium manufacturer shows us how much range can be achieved with current battery technology. And to achieve a record range of 1000 km (consumption below 10 kWh/100 km), Mercedes focused on reducing losses.
If an electric car like the EQS has an efficiency of 70% and an ICE drive train 30%, the Mercedes Vision EQXX has an efficiency of 95%. This means that 95% of the energy from the battery goes to the wheels.
How did this incredible efficiency come about?
First of all, the battery with a capacity of almost 100 kWh (the large battery from EQS has 107 kWh) has a 50% lower volume than EQS and is 30% lighter. Compared to EQS, the energy density is almost double, from 200 Wh/l to almost 400 Wh/l.
While, Mercedes EQS battery works with a voltage of 400V, the Mercedes Vision EQXX battery has a voltage of over 900V. For example, this high voltage creates great advantages when you want to charge the battery reducing the charging time.
The electric system that powers many of the ancillaries in the Mercedes Vision EQXX draws additional energy from 117 solar cells on the roof. On a single day and under ideal conditions, this can add up to 25 km of range on long-distance journeys.
Mercedes EQS has a Cx of 0.20 and Mercedes Vision EQXX achieved a record of 0.17. To this end, Mercedes has used advanced digital modeling techniques to reach a compromise that reduces drag while retaining the sensual purity of the Mercedes-Benz design language and the practicalities of a road car.
“It usually takes a year to complete a shape”, says Teddy Woll, head of aerodynamics at Mercedes, but in the case of Vision EQXX they had less than 6 months.
Another important aerodynamic element is the retractable diffuser – deploying only at higher speeds when the air becomes a considerably tougher opponent. When retracted, it fits seamlessly into the bodywork, preserving the balance, proportions and lightweight aesthetic of the rear end.
Also, an important role in obtaining the record Cx of only 0.17 is the shape of the body resembling a drop of water flowing backwards and ending with a long tail to reduce turbulence.
The frontal area is smaller than the CLA and the rear track is 50 mm smaller than the front track.
Another innovation is the air curtain/air breather at the front bumper. This ingenious layout pairs with the wheel covers to remove almost every last whisper of aerodynamic separation from the front wheels. Also, the front is very low as in the Mercedes-AMG One and the air pathways even guide additional cooling air over the bonnet, opening the cooling shutters if necessary. This reduces the interference drag around the mirrors and lowers overall drag compared to a conventional outlet into the underbody.
The Mercedes Vision EQXX is fitted with Bridgestone Turanza Eco tires mounted on 20-inch forged magnesium rims closed with a semi-transparent cover.
The 150 kW engine forms a integrated unit with transmission and power electronics featuring a new generation of silicon carbides. The power electronics is taken from that of the future Mercedes-AMG ONE supercar.
The electric engine is placed above the rear axle and send the power to the rear wheels.
At first sight the weight of 1,750 kg seems large but it is not so if we take into account the battery of almost 100 kWh. For comparison, BMW i3 with Life-Drive structure with CFRP pasenger cell has a weight of 1345 kg having a battery of only 37.9 kWh.
For example, the doors of the Mercedes Vision EQXX are made from a hybrid of CFRP and GFRP (carbon- and glass-fiber reinforced plastics) components with aluminum reinforcements. The MS1500 ultra-high strength martensitic steel is used on the body, which is extremely rigid but also very light at the same time.
Currently the largest aluminum structural casting at Mercedes-Benz, BIONEQXX is the major structural component at the rear end of the VISION EQXX – the rear floor. In addition to the BIONEQXX rear-floor casting, another BIONICAST component that features in the Mercedes Vision EQXX is the damper domes which accommodate the suspension components at the front of the car. Like the BIONEQXX casting, they too contribute significantly to keeping weight to a minimum, saving around four kilograms compared to conventional pressed domes. The bracket carrying the windscreen wipers and motor on the VISION EQXX was likewise designed using principles of bionic engineering.
In the same time, the brake system uses aluminium brake discs which reduce the mass significantly compared with cast steel discs. As well as being completely corrosion-free, this brake system also reduces brake dust emissions by up to 90% thanks to an innovative coating.
Meanwhile, new advanced glass-fibre-reinforced plastic springs developed in partnership with Rheinmetall Automotive remove further weight compared with conventional coil springs.
Inside, Mercedes presents a vision of what the MBUX system might look like in the future. The Mercedes Vision EQXX has a huge screen that spans the entire width of the interior and measures 47.5 inches with an 8K resolution (7680 x 660 pixels). It is true that Mercedes EQS has a 1.41-meter display that spans the entire width of the car but is not a single display but three screens hidden under a glass window. In the case of EQXX, it is a single screen.
For the navigation system, Mercedes-Benz team worked with navigation experts NAVIS Automotive Systems, inc. (NAVIS-AMS) to develop the first realtime 3D navigation system on a screen of this size. It performs seamless zoom and scroll functions from satellite view down to a height of 10 meters in the 3D city representation.
Mercedes promises a consumption of less than 10 kWh/100 km which means a range of 1000 km taking into account the battery of almost 100 kWh. An energy consumption of 10 kWh/100 km is the equivalent of a fuel consumption of 1 l/100 km, ie Mercedes Vision EQXX has been included in the category of 1 liter car.
It remains to be seen whether this extremely low consumption will be confirmed in a future small-series product. But we still have to wait for that.