Audi RS Q e-tron: Electric Desert Racer

The Dakar Desert Rally is one of the toughest motorsport events in the world. For safety reasons, the race no longer goes to Dakar, Senegal – only the legendary name always moved along. For some time, the race was held in South America, but now it is taking place in Saudi Arabia for the second time. It starts on January 1st in Jeddah on the west coast. In twelve stages, a total of 8,375 kilometers are to be covered by January 4th, 4,258 kilometers of which are under tougher conditions as special stages.

Audi for the first time at the toughest rally in the world

Audi is relying on three very special buggies. The three Audis with the model designation RS Q e-tron RS Q e-tron are powered by electric motors, which are supplied with electricity by a four-cylinder turbo engine converted into a generator. The engineers resorted to used TFSI engines from the Deutsche Tourenwagen Masters (DTM) for the combustion engines.

“With our drivetrain configuration in the RS Q e-tron, Audi is a pioneer at the Dakar Rally,” says high-voltage battery engineer Lukas Folie. “Defining the challenges for this type of competition was very demanding. There is simply no experience in motorsport for such a concept and for this type of long-distance competition.”

Designed for extreme demands

Audi turned its back on the successful team of Abt-Sportline and Formula E after the seventh season in favor of the desert rally. Compared to the Formula E World Championship, the standards at the Dakar Rally are different: daily stages of several hundred kilometers, significant driving resistance in the soft desert sand, as well as high ambient temperatures, and a vehicle minimum weight set by the regulations at two tons are extreme values in motorsport.

“With today's battery technology, it is not possible to realize a purely electrically driven BEV off-road vehicle for the Dakar Rally under these conditions,” says Lukas Folie.

The engineering team around Axel Löffler, Chief Designer of the RS Q e-tron, had to rethink the concept of the vehicle with electric drive and energy converter fundamentally for such a competition. Due to the short project development time, Audi relied on proven cell technology for the battery. The high-voltage battery's capacity is 52 kWh, roughly the same as a Renault Zoe. The battery consists of cylindrical cells with a very high energy density. The high-voltage battery, including the cooling medium, weighs about 370 kilograms. 

The three RS Q e-tron vehicles will be deployed by Q-Motorsport, a company owned by Sven Quandt, who has already won the Dakar Rally six times with his X-Raid team. Among the drivers will be Stéphane Peterhansel – a Dakar legend with six victories on a motorcycle and eight in various cars.

Charging with the TFSI Internal Combustion Engine

The rally drivers leave the bivouac every morning for each stage in electric mode with a fully charged high-voltage battery. Only a few minutes before the start of the stage do the teams receive details about the route with the issuance of the roadbooks. The Audi RS Q e-tron must always be prepared for all conditions with its drive system, whether it be distances, speeds, or the difficulty of the terrain.

The engineers have programmed specialized software to maintain the state of charge within defined areas, based on energy demand. The balance between energy consumption and recharging of the battery is maintained over specified distances. For instance, if a difficult dune passage with high driving resistance temporarily requires maximum energy, the state of charge will drop within a controlled range. The drive power of the two electric motors on the front and rear axles is limited to a maximum of 288 kW (392 PS) according to regulations. However, the internal combustion engine can only provide a charging power of 220 kW (299 PS). In extreme cases, consumption can temporarily exceed energy production.

"Such a situation is possible within a limited time frame," explains Lukas Folie. "But over a longer distance, it always results in a zero-sum game: we have to regulate the power consumption downwards so that the state of charge of the battery remains within a corridor. The total amount of energy available on board must be sufficient to complete the daily stage."