Tesla Roadster downforce fans join rare suction car trend

Tesla says the Roadster uses a multi-mode fan and ground sealing system that works as a downforce generator. Fans pull air out from beneath the car, which lowers the pressure underneath and presses the car down. Tesla says the effect is strong enough to hold the car upside down, even when it is standing still.

Downforce is simply the force pushing a car into the road. More of it means more grip for braking and cornering. Wings and diffusers on a normal supercar only make downforce once the car is moving, and they make more as speed rises. That leaves the least grip in slow corners and under hard braking. A fan works at any speed.

Tesla says the system can produce up to 2g of downforce. Alongside the fans sit a retractable rear wing, active aero, yoke steering with no mechanical link, and a Track Mode that drops the ride height and retunes the suspension.

A Tesla patent granted in late September shows one version of the idea: four electric fans side by side in the rear diffuser, fed by an inlet between the rear wheels and powered by the main battery. That design needs no skirts sealing the car to the ground. An earlier Tesla patent described fans with deployable skirts instead.

The first famous fan car was the Chaparral 2J. In 1970, racers Jim Hall and Hap Sharp entered it in the Can-Am series. It looked like a box on wheels, used two fans to pull air from under the car, and had see-through polycarbonate skirts to seal the space beneath it. The setup produced between 1.25g and 1.5g of suction.

Formula One followed in 1978 with the Brabham BT46, nicknamed the Fan Car and designed by Gordon Murray. Its team said the big rear fan was mainly there for cooling, which kept it within the rules, but it also sucked air from under the skirted car, and the suction grew with speed. It raced once, won the 1978 Swedish Grand Prix with Niki Lauda driving, and was withdrawn right after. Murray later fitted a 400 mm rear fan to one of his own road cars.

The closest modern rival is the McMurtry Spéirling, an electric sports car from England. Its Downforce-on-Demand system uses two fans to suck air out from under the car. It broke the all-time hill climb record at Goodwood in June 2022, makes 2,000 kg of downforce at a standstill and has been shown clinging upside down to a rotating platform. McMurtry says it can corner at more than 3g. When Tesla revealed the Roadster, McMurtry posted a video of its car hanging upside down with a short message welcoming Tesla to the club.

Musk has said the Roadster goes into production in 2028, and Tesla lists Giga Texas production for 2027 or 2028. There are three versions:

• Performance: a two-seater with the suction system and active aero, 0 to 60 mph in under 1.6 seconds, by reservation.
• Thrust: adds rear cold gas thrusters for 0 to 60 mph in under 0.9 seconds, as a limited release.
• Rocket: a one-seater with thrusters around the body, invite only and not offered in all regions.

A base Roadster reservation costs $50,000, and the Thrust trim costs $250,000 to reserve. Tesla has not given a full price. It also says the car is not approved for public road use.

McMurtry is further along. It unveiled the final production Spéirling Pure in July 2026, will build only 100, and expects first customer deliveries before the end of this year. Reports disagree on its price, so treat any figure you see with care.

For most drivers, the honest answer is that this stays on the track for now. Fan cars have been banned or withdrawn before, and keeping a sealed underbody working on a bumpy public road is far harder than on smooth tarmac. So far Tesla has shared no lap time and no independently checked cornering number, which means the record claims remain promises.

The Roadster also has a long record of delays. It was unveiled in 2017, promised for 2020 and is now set for 2027 or 2028. Musk himself has called it a halo car that may not move revenue much, and he has warned that buyers whose top priority is safety should not get one.

Tesla is not the only big name thinking this way, either. Bugatti CEO Mate Rimac said in an Instagram video after the reveal that he wrote an email about a fan-based static downforce system in 2019, inspired by the Brabham, and that his team studied cold thrusters for the Nevera’s successor in 2020. Both projects were shelved when work began on Bugatti’s V-16 engine.