The Mercedes-Benz Vision EQXX concept completed a 626-mile trip on a single charge, the automaker announced Wednesday in a press release.

The car averaged energy consumption of 7.1 kwh per 62 miles over the trip from Sindelfingen, Germany, to Cassis, France, on the Côte d'Azur, according to Mercedes. At the end of the trip, the battery reportedly still had a 15% charge, equivalent to around 25 miles of range.

That makes for slightly better real-world results than the 621-mile range estimate Mercedes quoted when the Vision EQXX was unveiled at the 2022 Consumer Electronics Show. That's with a battery pack of less than 100 kwh.

Mercedes Vision EQXX EV concept

Mercedes Vision EQXX EV concept

The drive, which was independently monitored by TÜV Süd, took the Vision EQXX over the Swiss Alps and throughout Northern Italy, creating plenty of opportunities for energy recuperation through regenerative braking while descending. The trip also included some stretches of German Autobahn, but cruising speeds were kept to a relatively sane 87 mph (the average speed over the whole route was 54 mph).

The EQXX emphasizes efficiency in every element. That starts with lightness. The concept's 3,850-pound curb weight slightly undercuts the Tesla Model 3—while offering more battery and range.

Mercedes Vision EQXX EV concept

Mercedes Vision EQXX EV concept

The battery pack itself is also half the size and 30% lighter than the pack used in the Mercedes-Benz EQS luxury sedan, with a claimed 20% increase in cell energy density. Mercedes also worked without a liquid cooling system, at least for the battery, because pumping liquid around uses more energy. An inverter designed with experience from Formula One racing also delivers a claimed 95% battery-to-tires efficiency.

Active aerodynamic elements give the Vision EQXX an extraordinary drag coefficient of 0.17, while a solar roof adds a claimed 16 miles of driving range per day.

The Vision EQXX isn't a production car, so it's not fair to combine it with range-leading production vehicles such as the Lucid Air or Tesla Model 3. It wasn't necessarily designed for that and all the considerations it entails, from safety and regulatory issues to durability, but most elements from it are expected to appear in compact and mid-size EVs based on the Mercedes-Benz Modular Architecture (MMA) beginning in 2024.