The overarching goal set for the Mercedes EQXX team was to achieve a single-digit kWh/100 km consumption figure (9 kWh/100 km=233 mpg-e). The Riviera Run yielded an overachieving 8.7 kWh/100 km (241 mpg-e). The team prioritized its efforts proportionately to the forces acting on such an electric compact sedan at speed: 62 percent of the energy expended goes to overcome aerodynamic forces, 20 percent to overcome the vehicle’s weight and rolling resistance, and 18 percent goes to the drivetrain losses.
Lowest Drag Without Fender Skirts
Aero was obviously the development team’s No. 1 priority, and wheels are a huge problem (front wheels typically create one-third of a sedan’s aero drag). The easiest (and ugliest) way to fix this is by faring the wheels into the bodywork with skirts or spats, but the team in Nice managed to minimize wheel drag with very smooth, unvented wheel covers, by specifying the tire sidewall contours and demanding all labeling be carved into the rubber, not embossed on it, and by insetting the rear wheels almost 2 inches relative to the fronts, putting them in the “wind shadow” of the front wheels. The considerable plan-view taper of the greenhouse makes possible those sensuous rear shoulders that mask this “design don’t” (it also benefits aero), but at considerable cost to rear seat shoulder room.
The next biggest aero advance (good for 0.01 Cd) is the rear diffuser, which extends almost 8 inches and drops down 3 degrees at speeds above 35 mph to work with the rest of the sharp edge that rings the tail of the vehicle to manage airflow separation and minimize drag-inducing turbulence. The rest of the story is more conventional: smooth underbelly and A-pillars, smaller, more aerodynamic mirrors, an underbody “cooling plate” that rejects heat directly to air passing under the car, meeting most of the vehicle’s cooling needs so the conventional radiator need only be used for climate control or extreme heat. That’s fed by shuttered openings in the lower grille that exhausts air through hood vents. The end result: a drag coefficient below 0.17 and a frontal area of 2.10 square meters for a total drag reduction of 29 percent relative to the EQS sedan (0.20, 2.51 sq m).
Weight Savings
Mercedes claims the EQXX tips its scales at 3,870 pounds—a bit less than the 3,902-pound single-motor Tesla Model 3 Long Range we weighed in 2017 with a smaller 75-kWh pack. A more energy-dense battery pack that relies on passive cooling is partly responsible. At 1,091 pounds including the one-box charger/controller, it weighs about the same as a Model 3’s actively cooled 75-kWh pack. The body structure employs a megacasting in the rear that, unlike the one in the Tesla Model Y, features “bionic design.” The team utilized ZBrush “digital sculpting” software (like Disney/Pixar used to render Shrek) to shape this megacasting, as well as the cast front shock towers, die-cast rear shoulder-belt anchors, and the 3-D-printed aluminum windshield wiper motor support. These parts only feature metal where mechanical stresses require it, with lightening holes where no stress flows. Where necessary, these holes are covered by UBX polymer panels produced from post-consumer waste. There are also composite springs, a carbon-fiber rear motor carrier, and aluminum brake rotors.
We’re taking premium electric architecture to a whole new level, surpassing what was once impossible. Together with the Formula 1 experts at Mercedes-AMG High-Performance Powertrains, we set out to break barriers — and in doing so, achieved unparalleled efficiency in the all-electric VISION EQXX concept vehicle.
From the onset, our design focus aimed for minimal environmental impact. The simplest solution for greater efficiency would be to build a larger battery — but we were not about to take the easy route. Instead, we developed the fundamentals of the VISION EQXX from scratch, pushing for unthinkably lightweight, hyper-efficient components. We achieved an energy-dense battery that’s 30% lighter and sized 50% smaller. Further refinements from our aerodynamicists allowed us to drop the drag co-efficient to an unimaginable cd 0.17. Just 18 months in the making, this concept car exceeds an astounding WLTP-estimated 620-mile range. With a number like that, this vehicle has the potential to become the silver bullet to the electric road trip — capable of journeying great distances on a single charge. Day-to-day, the average U.S. driver may need to fully recharge just twice a month.
Streamlining this vehicle goes beyond what’s under the hood. We added rooftop solar panels to power numerous functions inside. Interior materials were influenced by nature and made with animal-free textiles — like cactus fibers, mushrooms and vegan silk — that provide a luxurious finish from upholstery to door handles.
The VISION EQXX is more than efficient, it’s also very, very cool. True to its heritage, this Mercedes presents modern luxury, advanced tech and superior comfort. It demonstrates our transformation toward software-driven design with tech developments. Silver, rose-gold and gloss black accents reveal a progressive interpretation of modern luxury.
The extent of skills behind this vehicle are expressed in the XX of its name: it is the X-factor across an agile X-divisional collaboration. The VISION EQXX made its digital world premiere in January 2022 and represents a blueprint for the future of electromobility.
Motor/Battery Optimization And Solar Roof
Mercedes EQXX has yet to divulge full specifications on the EQXX’s battery and motor, except to say that they operate at 900 volts to further reduce amperage, cabling size (and mass), and overall system losses. The battery still utilizes nickel-manganese-cobalt chemistry employing high-silicon anodes and is said to deliver 95 percent of input energy to propulsion (90 is more typical). The 241-hp Mercedes-developed eATS 2.0-based motor employs a novel stator winding leveraging Formula E technology that places more copper near the rotor for greater power and efficiency. The roof and rear window area are covered in 19.4 square feet of 25 percent efficient photovoltaic panels intended to largely power the infotainment and other non-propulsion systems, extending the car’s range by up to 16 miles on a sunny day.
Riding Along In The EQXX
As engineering development vehicles developed from scratch in 18 months go, this one seemed uncannily production ready. Its 47.5-inch 8K-resolution pillar-to-pillar micro-LED (not OLED) screen rendered dazzling navigation info, with an intuitive interface and zero-lag responsiveness. Five different data-visualization tech screens displayed oodles of engineering and eco-coaching info in sharp gamer graphics. The sun’s angle of incidence and wind direction are used to precisely forecast solar energy gain, and the aerodynamic effects, the road grade, and traffic forecast help estimate instantaneous range remaining throughout the journey.
And the navy and white interior design is concept-car eye-popping while demonstrating a host of new eco-friendly materials (bamboo-based carpet, vegan “leather” from cactus and mushroom materials, and textiles spun from E. coli-produced faux silk) appear to meet luxury expectations right now. The level of noise and vibration could use a tiny bit of work, but the suspension soaked up bumps with reasonable comfort, and the car cornered nice and flat. Performance seemed roughly on par with that one-motor Tesla Model 3. On the downside, the low-energy, “personal listening” headrest speakers didn’t deliver Burmester fidelity, the back seat is laughably unusable, one must duck under the low door frames, and we didn’t get a peek in the trunk.