Setting incredibly ambitious goals is a way to motivate people to achieve things they might not have thought possible before. Land on the Moon and return safely to Earth before New Years 1969? Seemed impossible. But determined NASA employees and contractors made it happen.
The term “moonshot” is hopelessly overused, but that kind of daring mission is exactly what happened when Mercedes-Benz executives decided the company would build an electric concept car capable of going 1,000 kilometers (621 miles) of driving on public roads without charging. Oh, and they would have to design the car from the ground up, build it, and prove its capabilities on a real 1,000km road in just 18 months. Mad!
The result is the low-slung Vision EQXX. It’s only 53 inches tall and its slippery design results in an anti-wind coefficient of drag (CoD) of just 0.17. In the automotive industry, anything below 0.30 is considered excellent. The score of a soccer ball varies between 0.18 and 0.20. Mercedes’ stunning EQS production model achieves a CoD of 0.20.
Mercedes’ current lineup of electric vehicles includes the EQS full-size luxury sedan as a production model today, and the company has a flurry of battery-electric models hitting showrooms imminently or arriving in a not too distant future. These include the EQS full-size SUV, the mid-size EQE sport sedan, the mid-size EQE SUV, and the EQB compact SUV.
I had the opportunity to slip behind the wheel of the EQXX, a bullet-shaped engineering marvel at the Mercedes Immendingen proving ground in southern Germany, and to my surprise, I Found a polished machine that looks pretty much showroom ready. than the unique technical breakthrough that the EQXX truly is.
To achieve this seemingly impossible goal, Mercedes has attacked efficiency at every opportunity in pursuit of the “virtuous circle” of benefits that result from minimized weight and drag that reduce the demands on a battery and a bigger and heavier engine. However, and it’s partly because the car looks like something that could go on sale next year, they consciously opted to skip a few highly visible design elements to reduce drag.
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The company wanted anyone seeing the Vision EQXX to think of it as a real car, not an experience. So the aerodynamics team limited the car’s drag-reducing rear cone to two unseen inches, they avoided rear fender skirts that reduce aerodynamic drag resulting from rowdy rear wheels in the air, and they mounted plain old-fashioned glass mirrors on the doors instead of using cameras for the mirrors. The hearty original 1999 Honda Insight Hybrid-Electric is the look they were looking to avoid.
Then, even with one hand proverbially tied behind their back, engineers, aerodynamicists and stylists were still churning out that world-beating 0.17 CoD number. To do this, they notably replaced a lower cooling plate with the usual radiator. Air flows along the underside of this plate rather than through the cooling fins of a radiator, which significantly reduces drag. On-demand cooling means the EQXX has air exhausts in the hood that can draw air from under the front of the car when needed in hot weather. This only adds 0.007 to the drag coefficient of the car.
And the car rolls on Bridgestone’s narrow, low rolling resistance Turanza Eco tires which offer the twin benefits of reduced aerodynamic drag and reduced friction. During the test drive, I experienced the benefits of these tires first hand when driving down a very slight straight line downhill, when the car went from 57 km/h to 60 km/h where a regular car would probably stop soon rather than gain speed.
As with most electric vehicles, the EQXX has several energy recovery settings. Normally I like to drive in a mode that offers high regeneration when the driver takes a foot off the accelerator pedal, but Julien Pillas, an electric drive special projects engineer who keeps my time in the project car very expensive company, teaches me that I can improve the efficiency of my player by selecting the “coast mode” at certain points of the player.
This allows the car to exploit its glide and takes advantage of the fact that there are no conversion losses by directly using gravity to power the car on descents, rather than converting that energy into electricity stored in the battery, then deploy that juice. to the electric motor later.
The EQXX is fully instrumented and Mercedes produces a data table of my driving. They are impressed that during my 20 minutes behind the wheel, the car consumed energy at a rate of 7.78 kilowatt hours per 100 kilometers of driving, which exceeded the benchmark of 7.9 kWh set by their driver on the same route. To be fair, I averaged a slightly slower speed during my ride, but my trip also included a full-throttle 0-60mph acceleration on a steep grade to get a seat-of-the-pants feel of the EQXX all quite acceptable acceleration.
Unlike immensely powerful and fast vehicles like the 1,000 horsepower Hummer EV, the EQXX’s single electric motor powering its rear wheels is rated at a modest 241 horsepower. However, that motor is only tasked with displacing an equally modest (for an EV) curb weight of 3,858 pounds. The EQXX uses exotic carbon fiber construction and has so-called bionic moldings whose optimized shape mimics biological structures, but a big source of control over the car’s weight comes from its battery, which is a relatively soft 1,091 pounds. .
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For a 100 kilowatt-hour pack, that’s an incredible feat. Mercedes achieves this by using a 920-volt battery with silicon carbide power electronics to produce a battery that is half the physical size of the Mercedes EQS production model battery and takes up 30% less space than its production counterpart.
The pack is the work of Mercedes-AMG High Performance Powertrains (HPP) in Brixworth, England. These are the wizards who have helped the Mercedes Formula 1 team win the last eight constructors’ championships thanks to their mastery of hybrid-electric drivetrain.
“One of the best ways to improve efficiency is to reduce losses,” says Eva Greiner, chief electric drive system engineer at Mercedes-Benz, in the car’s press release. “We have worked on every part of the system to reduce energy consumption and losses through system design, material selection, lubrication and heat management. And our fantastic simulation tools have helped us quickly find out what works and what doesn’t.
The car’s light weight and narrow tires contribute to light steering effort. Along the way, the electric power steering assist decreases and steering feel is communicative and responsive. At park speeds, the assistance is overboosted, leaving the steering disconnected. In a production car, I’m hoping for an over-the-air update to improve this. In a breakthrough prototype that rushed to meet a deadline, it’s the closest thing I can find to a complaint. Amazing.
Power application via the accelerator pedal is smooth and linear, and regeneration when I lift the pedal is driver-selectable. In any regeneration mode, the car offers no surprises, with the refinement you’d expect from a Mercedes production car.
The doors of the EQXX open and close with authority. The interior is spacious and well detailed (even if the seat foam is curiously hard). My sense of reliability stemmed from the fact that the EQXX never failed and stalled its test riders, says Pillas.
The team tested the car’s drivetrain components in a prototype EQB SUV fitted with the experimental parts. This car suffered breakdowns, and even when it was running, drivers suffered from a lack of air conditioning in many cold European winter tests, Pillas recalled.
After this preparation, the team successfully completed their mission to drive the EQXX for 1,008 km (630 miles) in a route from Sindelfingen, Germany, through the Alps, to Cassis, France. But the team was not finished. Sensing their car had even more potential, Mercedes engineers ran a breathtaking 1,202 km (747 miles) on a single charge, piloting the EQXX from the company’s headquarters in Stuttgart, Germany to Silverstone. , in England. This trip benefited from more moderate temperatures and flatter terrain, averaging 52 mph and a top speed of 87 mph on the highway.
Can you imagine that when the engineers set out to achieve the seemingly impossible goals set for their concept car, they imagined that they would produce a machine so ready for the road that it could also be a preview of a ready version? for the showroom? I guess, as with the EQXX’s first record-breaking record, Mercedes still isn’t done with this car.
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