Motor Mouth: Benz’s Vision EQXX drives 1,000 km on a single charge

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Mercedes-Benz has just announced the unimaginable, an electric vehicle that can top 1,000 kilometres on a single charge. And it’s not some lab “simulation” or tiny little shoebox of a university experiment form-fitted around some skinny first-year engineering student as “proof of concept.” Nope, we’re talking about a real four-door sedan driven on real roads at real speeds and delivering, if the reports are at all credible, a real-world range of more than 1,000 km.

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And then some! Driven the 1,008 km from Sindelfingen in Germany; to Cassis on France’s famed Cote d’Azur, Benz’s EQXX actually had about 15 per cent left in its “tank,” good for another 140 km. Yes, that really does seem to imply its real-world range is almost 1,150 km.

As outlandish as that distance may seem, it is not the car’s most amazing accomplishment. Nor is the fact it did all of this with “only” 100 kilowatt-hours of battery onboard, even though legion are the numbers of newly released EV pickups and SUVs boasting 200 — and, in the case of GMC’s Hummer EV, even more — kilowatt-hours that can’t come close to matching that same range. It’s not even the fact that, if you do the math — dividing those 1,008 km by the 86 kWh used — the EQXX’s on-the-road efficiency works out to just 8.7 kWh/100 km, a claim that, were there not photographic proof of the voyage, would seriously strain credibility.

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No, the most amazing accomplishment is not only did the EQXX really drive that enormous distance, but it did so in the harshest conditions. For one thing, much of the route took place on the German autobahn, where Mercedes claims the EQXX was held at a steady 140 km/h. As we’ve found out in our Range Finder columns — which tests range and energy efficiency at a steady 125 km/h on Ontario’s Highway 407 — speed penalizes EVs even more than it increases ICE fuel consumption. That the EQXX manages 140 km/h without sucking back the electrical equivalent of the Exxon Valdez is pretty darned impressive.

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Even more interesting might be the fact that a significant portion of the route saw the EQ drive through the Swiss Alps. Officially, Mercedes says the inclines involved averaged five degrees. That might not sound like much, but the Alpine tunnel involved is the St. Gotthard’s and, having rifled through that one myself on my motorcycle, I can tell you that this stretch is an 18-wheeler-in-low-range motorhomes-literally-crawling-along type of incline that halves the fuel economy of even the most parsimonious of diesels and absolutely kills EV range.

That it was only 3 degrees C when the car reached the peak — cold temperatures being a battery’s biggest bugaboo — just makes the entire accomplishment that much more impressive. And while it is true that the Alps and the autobahn might have been a mere portion of the EQXX’s meandering sojourn, in my experience either would have been enough to short-circuit an ordinary EV’s supply of lithium ions.

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As remarkable as all this may be, there is one disappointment to this voyage. Like many, I was kinda hoping there would be one signature technology, a breakthrough chemistry as it were, that made this accomplishment possible. Something that, if applied to all future EVs, would be in and of itself a universal cure for range anxiety that we might get on with this revolution in powertrains without being worried about getting stuck on the side of the road.

Unfortunately, like so many things, it was yet another example of common, everyday systems engineering, the fancy bon mot project leaders trot out whenever they want to credit something a little more exotic than “attention to detail.” So, like I said, the EQXX’s battery, at 100 kWh, isn’t particularly large. What’s really important is that it’s physically small as well. Thanks to its superior energy density, compared with the battery in the recently released EQS 580, for instance, the EQXX’s is 50 per cent smaller and 30 per cent lighter, yet it holds only 7.8 fewer kilowatt-hours.

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In fact, the entire EQXX weighs in at only 1,755 kilograms (3,870 pounds). That compares quite favourably with the EQS’ SUV-like 2,585 kg (5,685 lbs). Not having to drag those extra 1,815 pounds up the Gotthard is the reason why the EQS is only rated for 547 km — and, in my Range Finder test, eked out just 332 km — while the EQXX’s battery still had 15 per cent more lithium-ions in its tank after traveling those 1,008 km.

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The reason why it was able to cruise the autobahn so economically is simple aerodynamics. Looking more like a relic of top-speed records past than a modern production automobile, the EQXX’s coefficient of drag is a super-slippery 0.17. (Most production sedans, even the most aerodynamioc, clock in at the low 0.20s.) Considering that aerodynamic drag goes up with the square of speed — and the power required to overcome that drag increases with its cube — the EQXX’s ultra-low Cd is the main reason it was able travel so far so fast so efficiently.

Of course, with these optimizations comes compromise. For one thing, the EQXX’s styling is, at best, unusual, with a face only an aerodynamicist could love. Its rear diffuser looks like it was pirated from a McLaren Senna, and the fact that its hindquarters are 50 millimetres narrower than the front is an awkward reversal of the norm for modern luxury cars. That said, its overall form is an accurate emulation of a raindrop, nature’s own perfect aerodynamic shape. Likewise, the car’s Bridgestone 185/65R20 tires are impossibly narrow and, according to Mercedes-Benz itself, so hockey-puck-hard that they probably make Goodyear Integritys look like Pirelli PZero gumballs.

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But it all works. In fact, it’s amazing and perhaps the most dramatic real-world proof of concept for long-range EVs yet. Unlike so many other supposed range experiments that involved all manner of trickery — like the L.A.-to-New York Cannonball Run in the then-new Tesla Model 3 in which the driver wore three pair of pants so he wouldn’t have to turn on the range-sapping HVAC system — Mercedes’ feat seems to be a legitimate test of real-world range. In fact, the EQXX was accompanied by an agent for the German TÜV — imagine the U.S. Environmental Protection Agency on steroids — and had its charging port sealed at the start of the journey

We’ve been waiting a long time for a solution to EV range anxiety. The EQXX’s 1,008 kilometres of real-world driving might be the first real step towards a solution.