Mercedes Vision EQXX breaks own efficiency record with 8.4mpkWh

The Mercedes Vision EQXX electric car concept has broken its own range and efficiency record, travelling 627.6 miles across the Arabian Peninsula with an impressive efficiency average of 8.4 miles per kWh. 

It was the car’s third long-distance road trip, following two previous attempts in Europe, and the second time the sleek sports car has travelled for more than 1000km (621 miles). 

This time, the Vision EQXX travelled 1010km (627.58 miles) in 14 hours and 42 minutes (12 hours 45 minutes in motion), at an average speed of 42.6mph (49.3mph in motion). 

At the end of the test, the car’s on-board computer claimed a remaining range of 192 miles, indicating a total range of 819 miles. Mercedes says the 8.4mpkWh average is equivalent to 282mpg in a petrol-fuelled vehicle. 

The EQXX’s previous drives, from Stuttgart to Cassis (1008km, or 626.34 miles) and Stuttgart to Silverstone (1202km, or 746.89 miles), had returned efficiency figures of 7.1mpkWh and 7.5mpkWh respectively.  

Its third drive included urban and suburban areas of Riyadh and Dubai, with stints in heavy traffic and open-road driving across the desert. Mercedes says the real goal was to maximise efficiency and research the thermal management of Mercedes’ specifically designed EV system. 

Mercedes also analysed the performance of the car’s solar roof, which consists of 117 solar cells and supports the high-voltage system. Across the desert, the roof took in 1.8kWh of energy, which Mercedes says added around 15 miles of additional range. 

The EQXX’s air conditioning - a feature that often heavily impacts the range of electric cars - was switched on for the entire trip “with minimal negative impact on energy efficiency”, supported by a newly developed heat pump.

This heat pump, a developed version of which has appeared in the Concept CLA Class that was revealed at the 2023 Munich motor show, is likely to make its way onto future Mercedes electric cars. 

The Vision EQXX is powered by a 100kWh battery. It’s driven by a single permanent magnet synchronous motor with 241bhp and 368lb ft of torque - roughly the same as an entry-level, single-motor Tesla Model 3.

It hits 0-62mph in around 6.8sec and is used as a testbed for research into electric vehicle architecture and to develop Mercedes’ future electric vehicle line-up.