We take a ride in the Mercedes-Benz Vision EQXX, an advanced sedan concept that points to the long-range capability of the German car maker’s next generation of electric-powered production models
Tea Mercedes-Benz Vision EQXX is a road car of the future that exists today. Its mission? To deliver the longest possible range using the least amount of electricity.
After two years of conception and development, the fully operational sedan concept was finally put to the test last week on a development drive from Mercedes-Benz’s headquarters in Stuttgart, Germany to its design studio in Nice, France – a distance of 1008km, which it managed to achieve on a single charge of its 100-kWh battery at an average speed of 87.4km/h.
In the process, the Vision EQXX returned average consumption of 8.7kWh/100km. What’s more, it is claimed to have arrived at its destination on the Cote D’Azur with 15 per cent of battery charge remaining, or over 140km of additional range, according to Mercedes-Benz.
To put this into perspective, the recently introduced EQE sedan, which uses a 90.6kWh battery, boasts an official WLTP consumption figure of between 15.9 and 18.7kWh/100km, giving it a range of up to 660km.
They’re impressive figures, no doubt. But they’re not half as interesting as seeing the Vision EQXX up close under a blue sky for the first time.
Rather than simply adopting a teardrop shape with fared in wheels for maximum aerodynamic potential with compromises in packaging – a route taken by cars like the GM EV1 and Volkswagen XL1, Mercedes-Benz has delivered a car designed to offer similar levels of accommodation and everyday practicality as its regular production cars, complete with four conventional front-hinged doors.
The front takes on a sportscar like appearance, with a low leading edge, a short hood, shapely fenders and large wheelhouses. The signature Mercedes-Benz grille is replaced by a star graphic incorporated into the front bumper, while the digital LED headlamps are conjoined by a full-width LED light bar.
A so-called ‘air control system’ channels air through the front section before it exits from two outlets in the bonnet. Mercedes-Benz has also forgone wind-cheating cameras for traditional rearview mirrors. They’re much smaller than those found on existing production models, but they do the job without a big loss in aerodynamic efficiency.
The A-pillars are set well forward. The cabin tapers towards the rear, giving the Vision EQXX a heavily shouldered appearance over the rear wheels. Unusually, the rear track is 50mm narrower than that up front.
|VISION EQXX: the trip log in figures|
|Start||Sindelfingen, 7:00 am|
|Arrival||Cassis, 7:02 pm|
|Travel route||Sindelfingen, Gotthard Tunnel, Milan, Cassis|
|driving distance||1,008 kilometers|
|Total travel time/movement||12 hours and 2 minutes/11 hours and 32 minutes|
|average speed||87.4 km/h|
|Maximum speed on motorway||140 km/h|
|average consumption||8.7 kWh per 100 km|
|Battery charge level on arrival (SoC)||around 15%|
|Remaining range on arrival||around 140 km|
The uniquely designed 20-inch wheels used front and rear are completely blanked off to minimize wind buffeting within the wheelhouses and promote a smoother flow or air along the side. They’re fitted with 185/65 profile Bridgestone Turanza Eco tires whose compound and profile have been developed specifically for the new car.
It’s the rear that really stands out, though. A full-width light graphic runs across the trailing edge of the boot lid and down along the sides. But the real attraction is the diffuser. It automatically extends outwards to extend the bodywork and optimizes the aerodynamics.
The upshot of all this is a drag co-efficient of 0.17 – the lowest ever achieved by Mercedes-Benz on a road-legal car. Even more important, says its director of aerodynamics, Teddy Woll, is the Vision EQXX’s relatively small frontal area, which is put at just 2.12m2.
“In typical highway running up to two-thirds of the energy provided by the battery is used to overcome aerodynamic drag,” he says.
For comparison sake, Mercedes-Benz’s most aerodynamic production road car, the rear-wheel-drive EQS450+ sedan, boasts a drag coefficient of 0.20 and a frontal area of 2.51m2.
At 4977mm in length, 1870mm in width and just 1350mm in height, the Vision EQXX is 31mm longer, 91mm narrower and 162mm lower than the EQE sedan. It also rides on a wheelbase that is 310mm shorter than Mercedes-Benz’s new electric-powered sedan at 2800mm.
With carbon fiber and other lightweight metals used in its construction as well as aluminum brake discs among other weight-saving measures, the new Mercedes-Benz concept hits the scales at a claimed 1755kg – a significant 285kg less than the EQA250 hatchback.
The basis for the new concept is a unique rear-wheel-drive platform. It is claimed to incorporate elements of the MMA (Mercedes Modular Architecture) structure set to be used by production models starting in 2024. A unique constructed prototype lithium-ion battery, weighing 495kg, is mounted within the floorpan. Described as being “around 100-kWh”, it uses the latest CTP (cell-to-pack) silicon anode technology from Chinese company CATL (Contemporary Amprex Technology Co. Limited) and operates at 900-volts.
Power comes by way of an electric motor developed and built by Mercedes-Benz’s German-based engineering team and its HPP (High-Performance Powertrain) division located in Brixworth, England. Nestled within the rear axle, it is rated at 140kW.
All four doors open wide to provide a sizeable aperture and welcome ease of entry. The hard shell backed front seats, boasting firm cushioning but minimum support, are mounted low, and the floor is completely flat.
The view ahead through the heavy angled windscreen is excellent, while the view directly behind is non-existent because an array of 117 solar cells covers the area that would otherwise be taken by a rear window.
The dashboard is set low, contributing to a snug feel further perpetuated by the narrow dimensions. It supports both a multi-function steering wheel and a 47.5-inch wide, 8K curved digital display. Along with a digital instrument panel, it houses a realm of real-time data, including the all-important power consumption read-out. The heavy rake of the windscreen places the header uncomfortably close to your forehead, but otherwise, there’s a lot to like about the highly-stylized interior.
When it gets underway in the car park of Mercedes-Benz’s design centre, the futuristically styled four-door saloon, whose leather-lined cabin features four individual seats, is near to silent. There is a faint but distant whine from the electric motor and some accompanying whirring as the power electronics spring to life, but it is nothing that you don’t already get in production-based electric cars these days. In fact, the whole car both appears and feels production like in many ways. The doors close with a solid thunk and the fit and finish of the interior is of a high standard.
The man at the wheel, Friedemann Flache, is no stranger to the Vision EQXX. One of four engineers nominated to drive the Mercedes-Benz concept, he undertook the first stint of last week’s test drive.
“It is very straightforward,” he says. “It doesn’t demand a particularly special driving style or anything like that, though to get the best out of it, to really strive for maximum efficiency and range, you have to anticipate situations well ahead.”
Heading off onto public roads around Nice and beyond, it is the imbibing smoothness and overall refinement of the Vision EQXX’s advanced drivetrain that leaves the biggest initial impression. One-off engineering concepts rarely project such deep-seated engineering integrity, but this one feels entirely happy making progress along arterial roads.
When we get a clear run at higher speeds on the highway, Flache calls up a menu to deploy the rear diffuser. Its operation is shown on the dashboard display, so you can see it extending out.
All the while, the youthful Mercedes-Benz engineer keeps a keen eye on the electric energy being used. “We try to keep it in a sweet spot of around 10 to 15kWh/100km,” he tells me.
There are four levels of brake energy regeneration activated via steering wheel-mounted paddles. Most of the time, the Vision EQXX is engaged in D–. It provides strong deceleration when the throttle is lifted.
|VISION EQXX technical data|
|Energy content of the battery||< 100kWh|
|Rated voltage||> 900V|
|drag coefficient||0.17 Cds|
|Front facing||2.12m sq|
|Unladen vehicle weight||1,755kg|
Once you’ve become accustomed to the various regeneration modes, you discover you don’t need to physically operate the brakes much at all. There were a few occasions during the Stuttgart to Nice test drive where I consciously had to use them. For the most part, though, I relied on the paddles and the regenerative properties to slow the car down.”
Despite the clear focus on efficiency, the rear-wheel-drive Vision EQXX has a subtly sporting flavor to its on-road character. It proves quite brisk when the traffic opens up and Flache is able to fully deploy the full force of the electric motor.
As with all of Mercedes-Benz’s existing electric models, drive is channeled through a single-speed gearbox. A short stab of the throttle sees the low slung saloon shoot forward with proper intent before the traffic closes in, and we settle into a loping cruise. While it clearly has the potential to extend well beyond it, the top speed is limited to 140km/h.
“It’s more as a precautionary measure than anything else,” says Flache, who reveals the electric motor and its ancillaries were comprehensively tested in an EQB prototype before being granted approval for use in the concept.
You don’t hear much wind noise at all. Being the most aerodynamic road-legal car Mercedes-Benz has ever produced, the four-seat concept cleaves the air with razor-sharp efficiency. At typical motorway speeds, it is the dull roar of the narrow tires more than anything else that grabs your attention.
With a low overall height and a battery mounted completely with the flat floor structure, the center of gravity is lower than any existing Mercedes-Benz production model, so the Vision EQXX’s cornering ability is more than respectable. We’re in the passenger seat, but it changes direction smartly and gives the impression of being very fluid when it is pointed down a winding back road at a reasonable speed. Such is the integrity of the handling, it is easy to forget it is a technological test bed for future technologies rather than a prototype of an upcoming production model.
Minimum suspension travel ensures there’s very little roll. But in combination with firm springs and dampers and tires running high pressures to minimize rolling resistance, it also contributes to a rather fidgety ride. It is not harsh, as you might expect on a one-off concept. However, it could do with some added absorption of road shock.
Ingenious, compelling and entertaining, the Vision EQXX shows how electric cars are set to progress in coming years. It will never go into production, not as it is right now. However, many of its key developments are already being refined with a view to incorporating them into upcoming Mercedes-Benz production models.
The good news is that with the sort of advances in aerodynamics, tire technology, construction techniques, electric motors and batteries it showcases, a realistic range of over 1000km and more under real-world driving conditions on a single charge of a 100kWh battery is not only attainable but likely to be taken for granted in the not-too-distant future.
Let’s just hope this also applies to models that we will be able to afford.