Mercedes-Benz: EQXX breaks the 1,000-kilometer mark with 8.7 kWh/100 km

Against the Arms Race: 180 kW E-Drive is Completely Sufficient

The vehicle's electric drive system (eATS) developed jointly with F1 racing specialists from HPP – consisting of an electric motor, transmission, and power electronics – offers a peak power of 180 kW. Thanks to the torque available from a standstill and the model's very low driving resistances, the full potential almost never had to be tapped during the entire tour. However, other factors are much more important than maximum power, according to the manufacturer: The eATS, like the battery, is compact, lightweight, and highly efficient. The average efficiency for this application is 95 percent, according to the Swabians, in other words: 95 percent of the energy from the battery reaches the wheels.

According to Mercedes-Benz, this is accompanied by efficiency advantages such as the reduction of losses in the drive system. Engineers have managed to reduce the overall losses in the powertrain (motor, inverter, and transmission) by 44 percent compared to an e-drive that is not based on this project. The responsible parties noted: One percent more efficiency brings two percent more range. This effect is also supported by the battery thanks to its high energy density of nearly 400 Wh/l and the particularly high operating voltage of more than 900 volts.

Battery: Capacity like EQS, Size for a Small Car

The newly developed power storage with nearly 100 kWh has almost the same amount of energy as the EQS battery, which itself sets benchmarks in the global comparison of purchasable electric cars, according to Stuttgart. However, the EQXX battery has 50 percent less volume and 30 percent less weight. The effect: The compact battery, only 200 x 126 x 11 cm in size and relatively light at 495 kilograms, fits into a compact car. This, along with numerous lightweight measures, contributes to the slim weight of just 1,755 kilograms.

The technology used for the first time has otherwise proven itself throughout the entire journey, with no issues such as wiring overheating occurring. Additional efficiency gains were brought about by active cell balancing. It is intended to ensure that the energy is equally drawn from the cells during the drive. This increases the usable energy and thus the range, the manufacturer claims.

Solar Roof Harvests Energy from the Sun

The VISION EQXX received an energy boost around noon in the Po Valley near Milan – not from a charging station, but through its built-in solar roof. The 117 solar cells feed the 12-volt battery, which powers auxiliary consumers such as the navigation system. The added value was measurable: The high-voltage battery is accordingly relieved, which can be read on the onboard computer's display. Overall, the solar booster increases the range by more than two percent – which, on a journey of over 1,000 kilometers, amounts to a good 25 kilometers.

Efficient Thermal Management System: Passive Cooling is Enough

Thanks to the drive's high efficiency, the electric powertrain generates very little excess heat, so passive cooling was sufficient for the entire trip. The cooling plate in the underbody uses the airstream to provide uniform cooling. This aerodynamically efficient solution increases the range by 20 kilometers, and the c_w value remains consistently low at 0.17. Even when climbing to the Gotthard Tunnel, the air vents remain closed, according to the company.

The stretch between Amsteg and Göschenen involved a continuous 14-kilometer climb with grades of up to five percent. Beyond the Gotthard Tunnel, the road led downhill for kilometers, and the EQXX used the energy recovery to increase the range. A positive side effect: Thanks to the electric brake, the mechanical brakes are hardly used, allowing for the first-time use of new aluminum brake discs, which are significantly lighter than their steel counterparts.

Pedal to the Metal: Unfeasible with Speed Limits Anyway

How much energy a motor consumes in practice ultimately depends heavily on driving style. "Pedal to the metal" isn't an option in Switzerland, Italy, or France anyway, due to speed limits and strict controls. The vehicle provided the driver with tips for optimal driving style in the style of a co-pilot. The Efficiency Assistant informed about energy flow, battery status, topography, and even the direction and intensity of wind and sun. Shortly before reaching its destination in Cassis, the technology carrier gathers more energy through recuperation. After 11 hours and 32 minutes of pure driving time, it ends its 1,008-kilometer road trip with a remaining range of around 140 kilometers.