Tesla has been granted a patent for an "Electric Fan Car" system that uses four axial fans in the rear diffuser to pull air from beneath the vehicle, creating a suction region that presses the car to the road. The patent, filed in January 2024 with a provisional application from January 2023, describes fans powered by the main battery pack and integrated into the car's control system, with a manual or automatic activation mode. A second version adds side inlets to prevent the central inlet from drawing non-productive air from behind the car.
Although the patent drawings show a Model S, Tesla halted Model S and Model X production in April. The company has been accumulating aero patents, including an active rear wing and an earlier skirted fan concept, leading speculation that the technology is intended for the long-delayed Roadster, which is slated for a demo on October 15. Electrek notes the Model S drawings suggest a track-focused Model S was in development in 2023, but that car is no longer in production.
Fan cars are not a new idea; the Chaparral 2J and Brabham BT46B raced in the 1970s, and Gordon Murray's T.50 uses a fan for downforce. On the electric side, McMurtry's Spéirling has been producing 2,000 kg of downforce at a standstill and is already in production. Tesla's twist, according to the patent, is that its design works without sealing skirts, packaging the fans into a conventional-looking diffuser. Electrek, however, is skeptical that Tesla can match McMurtry's downforce numbers without such skirts.