Mercedes-Benz Vision EQXX shoots for peak electric car efficiency

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This is the Mercedes-Benz Vision EQXX, and it is the result of a huge technology project to improve the company’s electric vehicles. The result of the project is a real car that drives and complies with safety and traffic regulations. Is it a production car? No, it never goes on sale, but Mercedes says a lot of what it learned in putting the Vision EQXX together will one day find its way into production electric cars. To prove the technology, Mercedes will soon even attempt a 621-mile road trip across Europe with the Vision EQXX.

There’s a mountain of information and technology to dive into, but we’ll start with a quick rundown to explain why the Vision EQXX is special and what Mercedes’ work has accomplished from a larger perspective.

The goal was to build an electric car with a range of more than 1,000 kilometers and that was exactly what happened. For us Americans, that’s just over 620 miles. Mercedes engineers got there by going the efficiency route, not increasing the battery, which is the most impressive aspect of the Vision EQXX. In its current form, the EQXX has an astonishing efficiency of 6 miles per kWh. That’s significantly better than even the most efficient EVs on the market today, including Tesla. With that information in mind, let’s take a look at how Mercedes has developed an EV that is so efficient.

Mercedes-Benz VISION EQXX

We’ll start with the battery, because that’s the heart of an electric car. Mercedes says it has partnered with the Mercedes-AMG High Performance Powertrains Formula 1 team to put together a super-density battery pack. The pack itself is “just under 100 kWh” of usable energy, but it can be stuffed into a compact car like the EQXX. It has the potential energy of the EQs, but the packaging itself has 50% less volume and is 30% lighter than the one in the EQs. Mercedes attributes the improvements to advances in chemistry — we’ll reportedly see a battery with this new chemistry in production by 2024 — and a new OneBox compartment that improves the level of integration of the battery pack into the platform. It even has a “lid” that is made of durable composite material and then reinforced with carbon fiber.

We know other manufacturers have raised the bar to 800 volt electrical systems, but the EQXX is experimenting with a 900 volt system that works and works. Mercedes has not confirmed that a 900-volt system would make its way to production soon, but it did say it was assessing the technology for possible future use in a production car. The only missing factor in Mercedes’ battery conversation is charging. It appears that no breakthroughs have been made in loading time for the EQXX.

Then there’s the drive unit itself, which consists of the electric motor, the single-speed transmission and the power electronics, the latter of which is pulled from the AMG Project One hypercar. However, the single electric motor itself is not super powerful, because Mercedes estimates it at 201 hp. The idea was to make it efficient, not a supercar. Mercedes uses a new generation of silicon carbides in the powertrain and says the efficiency of the powertrain as a whole is 95%. That means 95% of the energy goes from the battery to the wheels, a fantastic figure. Like the battery, this motor is planned for use in a production EV in the 2024-2025 range.

This super-efficient powertrain produces very minimal waste heat, which also means the thermal management system can be very lightweight. Aero shutters, coolant valves and water pumps keep the drive unit at the right temperature with very low energy costs. Mercedes says the battery itself is air-cooled, not liquid-cooled, because the liquid-cooling takes more energy than it’s worth in this engineering project. Instead, for proper cooling, Mercedes uses a cooling plate installed in the floor of the vehicle. This allows airflow from the underside to cool the battery, which Mercedes says is the most aerodynamic way to get the job done.

And since we’re on the subject of air management, it’s time to get into the aerodynamics of the Vision EQXX’s design. The drag coefficient is only 0.17. That beats the current leader in production cars – the EQS – which has a Cd of 0.20. Mercedes says a typical long-haul electric car on the highway spends about two-thirds of its battery capacity cutting through the air ahead. That’s why a smooth shape is so necessary for long distances.

Mercedes lists numerous design choices it has made to make the design of the EQXX as efficient as it is. The frontal area is smaller than that of the CLA. The track width is 50mm less at the rear than at the front. The air curtain at the front bumper is coupled to the wheel covers to remove any possible aerodynamic separation from the front wheels. Air ducts on the hood help reduce drag around the mirrors, and cooling hatches that open on the hood create less drag than if they were mounted in the underbody. Air flows over the car in a “tear-off edge” at the rear. It uses a retractable rear diffuser that deploys at high speeds. Mercedes even teamed up with Bridgestone to create unique Turanza Eco tires that have aerodynamically optimized sidewalls to match the covers mounted on the 20-inch forged magnesium wheels.

It’s a work of art if you’re a fan of aerodynamics, and we find it quite attractive at the same time. Mercedes was able to put together a beautiful as well as an intensive low drag car, which is exactly what we want to see as we move into an era of EVs.

Of course, efficiency also comes from being lightweight, and that’s something electric cars have traditionally been pretty bad at. In an effort to lighten the structure, Mercedes used an intriguing BIONEQXX aluminum structural casting as the main rear structural part, which we’ve already seen on the EQS. What is BIONEQXX? It is a casting that looks like a web of holes (read: holes) where no structural elements are needed. Material is only used where it is needed for the constructive function and where loads are applied. Of course, holes in the bodywork aren’t ideal when a car is driving in water and mud, so Mercedes uses a durable plastic alternative produced by 3D printing to fill the holes – 42 of them to be exact. This complex process saves about 15-20% of the weight of a traditional casting, says Mercedes. The same process is used for the damper domes, saving 8.8 pounds over conventional domes.

The doors are made of a combination of carbon fiber and glass fiber reinforced plastics. Mercedes uses aluminum brake discs that drastically reduce weight compared to cast steel discs – brake dust emissions are also reduced by 90% thanks to a unique coating used on the brake discs. Glass fiber reinforced plastic springs also replace conventional coil springs, which saves weight. Ultimately, the Vision EQXX weighs 3,858 pounds. That’s still not a lightweight, but it’s lighter than most luxury EVs on sale today.

Numerous efficiency-related efforts have also been made to the EQXX’s interior. The massive 47.5-inch mini LED 8K display has over 3,000 local dimming zones, meaning it only uses energy for the parts of the screen that light up. The detail of the navigation system adapts to the location of your journey as it reduces digital details during long highway trips to reduce the energy consumption used to produce 3D maps in urban areas. This screen itself is managed by a new game engine that opens up graphics capabilities to Mercedes that it didn’t have before. The 4D Burmester sound system has been updated by reducing the number of speakers (a first) and positioning the speakers closer to the occupants. To maintain the same quality we expect from Mercedes, the system uses two loudspeakers in each headrest and a bass generator in each seat.

In addition, the roof is equipped with solar panels. Mercedes claims that the panels can have a range of 25 kilometers on an ideal sunny day. In most cases, however, the solar energy is simply stored in a lithium-iron battery that supplies power to the climate system, infotainment system and other support systems. This means less power is needed from the large lithium-ion pack to power all those other systems, extending your overall range.

There’s also a lot to say about the actual materials used in the cockpit, as Mercedes shows us a new sustainable interior philosophy. The door handles are made of a “biosteel fiber”, a “vegan silky fabric”. The chairs are made of mycelium, a leather substitute that is made up of the underground root-like structure of mushrooms. Other leather has been replaced everywhere with Deserttex, a material made from pulverized cactus fibres. When asked, Mercedes says it’s not ready to replace leather yet, but plans to offer customers more sustainable options in the future. The rugs are made of bamboo fiber and your traditional Mercedes “Dinamica” is made of 38% recycled PET bottles.

When it comes to technology, that huge single screen stretching from pillar to pillar houses Mercedes’ latest innovation: a road trip sidekick. The “sidekick” is intended to be your guide who is responsive to the needs of the driver and passengers. One of those features is the improved “Hey Mercedes” functionality, as the voice is now much more real in nature, and machine learning gives the character a sort of personality. This so-called sidekick is intended to predict what you would like to display on the screen and has its own zone on the display. However, Mercedes says you can turn it off if you wish.

The final point of discussion with the Vision EQXX is the speed with which Mercedes has essentially developed a safety-compliant steerable car. Through new use of digital tools in design and engineering, the Vision EQXX was completed in just 18 months. This includes over 186,000 “test miles” run on a computer. It’s especially impressive when you consider how many teams were involved in the project, as this car was helped by both the F1 and Formula E teams to make it the best it could be.

Maximum efficiency in electric driving was the goal, and Mercedes’ efforts will hopefully lead to even better efficiency in electric car production in the near future.

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