As well as proving the effectiveness of Mercedes-Benz electric efficiency technologies in a wide range of real-life traffic scenarios, the VISION EQXX's long-distance journeys on public roads provide R&D experts with valuable data for the ongoing development programme.

The proof of success for the VISION EQXX came in April this year. A record-breaking maiden road trip saw it cover 1,008 kilometres from Stuttgart to Cassis on the French Mediterranean coast. With temperatures ranging from a chilly 3 to a more springlike 18 degrees Celsius, it completed that journey with energy consumption of 8.7 kWh/100 km and a remaining range on arrival around 140 kilometres. But once is not enough. To demonstrate true real-world capability and to take the development process to the next level, the engineering team are running a series of road trips to test the technology underpinning the VISION EQXX under different conditions.

This time, the route profile did not come with lower temperatures nor the demanding energy usage and recuperation scenarios presented by the Alps. The main challenges on this trip were summer temperatures of up to 30 degrees Celsius, paired with increased traffic density around Stuttgart and in the southeast of England. Nevertheless, the VISION EQXX kept a cool head the whole way thanks to its innovative thermal management system.

The exceptional efficiency of the electric drive unit means it generates only minimal waste heat. This helps keep the thermal management system extremely small and lightweight. The carefully engineered interaction of aero-shutters, coolant valves and pumps ensures the electric drive unit maintains the most efficient temperature balance at minimum energy cost. It encompasses a combination of innovative air-flow management and a cooling plate installed in the vehicle floor, enabling it to take advantage of the air flowing along the underside of the VISION EQXX. This is the most aerodynamically efficient way of keeping the electric drive unit cool under normal conditions, allowing an increase in range of around two percent in the most aerodynamic mode.

High ambient temperatures and stop-and-go motorway traffic necessitated cooling of the electric drivetrain and passenger cabin. However, the on-demand cooling system took it all in its stride with no significant impact on range. The multi-source heat pump in the VISION EQXX proved highly efficient at keeping the cabin temperature cool in the warm summer weather. During the 14 hours and 30 minutes of driving time, the air conditioning was operational for just over eight hours, yet had a minimal negative impact on overall energy consumption.

On the home straight to Silverstone, the VISION EQXX paid a visit to the home of the Mercedes-AMG PETRONAS Formula One Team in Brackley, some 13 kilometres to the southwest, where it received an enthusiastic welcome from the team from Mercedes-AMG HPP and Mercedes-Benz Grand Prix who played a pivotal role in its design. Working hand-in-hand with the engineering team in Stuttgart, the Formula 1 and Formula E specialists helped slash system losses in the drivetrain and develop a completely new compact and lightweight battery pack.

With two successful 1,000 km+ road trips under its belt, the VISION EQXX has well and truly justified its claim as the most efficient Mercedes ever built. But the story doesn't end there. Work continues on the development of many VISION EQXX technologies for application in future series-production vehicles. For the team behind it, gathering invaluable real-life data, the most important question is: Where next?