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If you were to switch from your internal combustion engined car to an electric vehicle, what would be an acceptable amount of range? Would 400 km be enough? How about 600 km? Mercedes-Benz has just announced a world-beating efficiency in real-world driving of 1,000 km (621 miles) on a single charge by its one-off Vision EQXX concept car.
On Tuesday, April 5, the all-electric EQXX left Germany, drove for 12 hours non-stop on one charge, across the Swiss Alps, and arrived in France with 140 km of range still left in its battery pack, according to Mercedes. It shows what is possible when state-of-the-art lightweight materials, a slippery body design, advanced battery technology, an F1-inspired electric motor setup, and aerodynamic tires are combined into one vehicle.
Traveling from Sindelfingen near Stuttgart to Cassis on the Cote d’Azur, the journey took the team from Germany to Switzerland, then through Italy past Milan, and finally onto the port town of Cassis near Marseille in the south of France. The EQXX was driven on normal roads ranging from highways to mountain passes, including roadworks, and even included a stint up to 140 km/h or 87 mph. According to Mercedes, the battery pack’s state of charge on arrival in France was about 15%, amounting to a remaining range of around 140 km, and an average consumption of a record-breaking low of 8.7 kWh per 100 kilometers.
Boasting a surprisingly low Cd value of 0.17 for a road-legal car—with a number around 0.20 considered aerodynamically sound—the EQXX is packed with innovations that enabled it to achieve the world-record range.
It starts with the basic teardrop body shape that features a smooth-surfaced greenhouse-shaped cabin that flows like a droplet towards the rear of the car. Equally beneficial to the aerodynamics are the small frontal area of 2.12 m2 and the reduced rear track. With the rear being 50 mm (2 inches) narrower than at the front, the rear wheels roll in the slipstream of the front wheels. The active rear diffuser, which automatically deploys at 60 km/h, provides better airflow and thus contributes significantly to the reduced drag.
Looking somewhat like a futuristic aerodynamic Aston Martin DB5, especially at the rear end, the EQXX also benefited significantly from its bespoke Bridgestone tires, with their extremely low rolling resistance rating of 4.7. Co-developed with Mercedes Benz, the Japanese tire maker created a unique 185/65 R 20 97 T Turanza eco tire boasting a large diameter and narrow tread that helps the car to slice through the air and generate the record-breaking range.
A large part of the weight efficiency is also due to the dedicated electric chassis with a lightweight F1 subframe and aluminum brake discs. Another is the battery. At 100 kWh, the power storage unit developed specifically for the VISION EQXX has almost the same amount of energy as the battery of the EQS. However, it has 50 percent less volume and is 30 percent lighter. The resulting compact battery is also comparatively light at 495 kilograms and fits in a compact car. The electric drive was developed in cooperation with engineers from Mercedes-AMG Petronas F1 Team.
Sending 241 hp to the rear wheels, the F1-spec electric motor has an average efficiency of 95 percent, and combined with the advanced battery, the whole powertrain barely generates any waste heat. That means the vents stay closed and drag is kept to a minimum.
The EQXX is just a concept for now. But the know-how gained from this road trip will impact on future EVs. Mercedes’s chief technology officer Markus Schäfer said that the company’s upcoming MMA electric platform would use batteries with similar chemistry to the EQXX’s in 2024. He also said: “Stay tuned. In the near future, you will see something which is – from a design standpoint – very very close to this vehicle.”
