The Mercedes-Benz VISION EQXX has beat its own efficiency record (earlier post) in real-world driving with another 1,000 km+ (621 mile+) journey on a single battery charge. Following its initial record-breaking drive from Stuttgart to Cassis (France) in April, the research vehicle set the bar even higher, with a 1,202- kilometer (747 mile) road trip from Stuttgart to Silverstone in the UK.
After negotiating an autobahn closure and requesting cross-country diversion near Stuttgart, the VISION EQXX crossed the French border near Strasbourg then cruised across northern France at highway speeds to Calais, where it boarded the Eurotunnel. Continuing its journey in the UK, it took the M25 around London then stopped off at Mercedes-Benz Grand Prix in Brackley. Waiting to greet it there were the Formula 1 and Formula E experts who helped develop its advanced drivetrain.
The VISION EQXX then carried on to Silverstone, where it was welcomed by special guest driver Nyck de Vries. The Dutchman, who races for the Mercedes-EQ Formula E team, opted not to go easy on the research vehicle, taking it up to its maximum speed limit of 87 mph on the iconic British race track. Making the most of the occasion, he completed 11 laps, using the last of the charge on the pit lane.
Throughout the road trip, the VISION EQXX took advantage of its innovative thermal management system to achieve an average consumption of 8.3 kWh/100 km in the face of heavy traffic and summer temperatures.
Along with 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 program.
The record-breaking initial road trip saw the VISION EQXX cover 1,008 kilometers (626 miles) from Stuttgart to Cassis on the French Mediterranean coast. With temperatures ranging from a chilly 37.4 degrees to a warmer, spring-like 64 degrees Fahrenheit, it completed that journey with energy consumption of 8.7 kWh/100 km and a remaining range on arrival around 140 kilometers (87 miles).
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 86 degrees Fahrenheit, paired with increased traffic density around Stuttgart and in the southeast of England.
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.
The system 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 highway traffic necessitated cooling of the electric drivetrain and passenger cabin. However, the on-demand cooling system took it all in 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.