IMMENDINGEN, GERMANY—Driving off in the Mercedes-Benz Vision EQXX was slightly more stressful than I had anticipated. Not that it’s difficult to drive or hard to see out of the low-slung streamliner—it’s just the only one in existence.

Mercedes wouldn’t tell us the program’s exact budget, simply warning us that the sole EQXX should be considered priceless, but I’d guess it’s somewhere in the range of three Bugatti Pur Sports.

Like the Bugatti, the EQXX was built to an engineering brief—in this case, the aim was to build an electric vehicle capable of at least 621 miles (1,000km) on a single charge. Also like the Bugatti, it’s road-legal: In April of this year, less than two years after the project was given the green light, the team drove the EV 625 miles (1,006 km) from Sindelfingen in Germany to Cassis, France, arriving with 15 percent state of charge in the battery.

Two months later, the team followed that up with a longer drive that involved descending down fewer mountains, driving from Stuttgart, Germany, to the Silverstone racetrack in the UK, where reigning Formula E champion Nyck de Vries then used the remaining charge to drive some hot laps. The car eventually completed 747 miles (1,202 km) before coming to a halt in the pit lane.

But this is not Bugatti, and there are no plans for a low-volume production run, not even at eye-wateringly high prices. The Vision EQXX is a one-off, a concept car come to life, but it’s more fully realized than any other concept I’ve yet encountered. A pure engineering exercise or world record breaker wouldn’t bother with a functional infotainment system that uses a single 44-inch 8K display, nor a completely trimmed interior, even if it’s one that uses a cactus-fiber fabric instead of leather, bamboo fiber carpets, and a biotech-derived silk, among other innovations.

And despite the priceless nature of this low-drag EV, Mercedes let Ars drive it.

Aerodynamic drag is the enemy

As you might guess from its looks, the Vision EQXX’s shape is more than a little aero-optimized. About 62 percent of the work the motor has to do is fighting against air resistance, after all. It’s a smaller car than it seems from the pictures—about a foot shorter than the production EQS, at 195.9 inches long. And that includes the long overhanging nose and tail, so the Vision EQXX’s wheelbase is actually compact-car short at 110.2 inches (2,800 mm).

A narrow 73.6-inch (1,870-mm) width and low 53.1-inch (1,348-mm) roofline give the car a small frontal area—22.8 sq ft (2.12 m²)—and the frontal area works with the drag coefficient, which in this case is just 0.17, making it one of the lowest-drag cars ever made.

From the nose to the C pillar, it might remind you of the Porsche Taycan, a very slippery customer itself. The door handles retract flush to the doors, or at least they do up front; the rear doors don’t open, one of the few tells that this really is a concept and not a production car.

The side-view mirrors are of a size you might expect to find on a racing car rather than something wearing a license plate, but they work well enough. That’s a good thing, as there’s no rear window. Instead, that space—and the whole roof—is given over to a 300 W solar array that feeds into the car’s 12 V battery, which, like the traction battery, is also lithium-ion. (Since the priceless one-off will never be left parked outside for very long, Mercedes didn’t bother adding the extra parts that would allow the panel to trickle-charge the traction battery.)

From the rear wheels back, the car is like little else, other than perhaps the Lightyear Solo. When parked, the lower part of the tail retracts into the bodywork; it extends when the car’s onboard brain decides it’s more efficient to do so.

https://arstechnica.com/?p=1869001