How to use
- Pick a preset (Tesla Roadster, Formula 1 car, road sports car or McMurtry Spéirling) or enter your own car mass.
- Choose how the car is held down: Wings (downforce that grows with speed), Fan suction (works when standing still) or Thrusters (to lift off).
- Move the road angle slider from 0° (flat road) through 90° (wall) to 180° (ceiling) and watch the diagram: the car sticks while the force on the tyres stays above zero.
- Read the speed or pressure drop needed to drive on a ceiling, or how long a cold-gas tank could keep the car in the air.
How the Tesla Roadster drives upside down
Tesla unveiled the new Roadster on 15 October 2026 at SpaceX's test site in McGregor, Texas. Fans pull air out from under a sealed floor, so the air pressure above the car pushes it against the road. Tesla says the system produced about 4,700 kg of hold-down force with the car stopped upside down on a ramp, and Elon Musk said it can pull up to 2 g. Tesla has not published the car's weight; 4,700 kg at 2 g suggests about 2,350 kg, which is the preset used here.
The physics is simple: suction force = pressure drop × floor area. Spread over a 4 m² floor, 4,700 kg needs a pressure drop of about 11.5 kPa, roughly 11% of normal air pressure. Because the fans do the work, the car sticks even at a standstill, which wings cannot do.
Wings versus fans: could an F1 car drive on the ceiling?
Wing downforce follows ½ × air density × speed² × ClA, where ClA is the car's downforce area. Double the speed and the downforce goes up four times, but at a standstill it is zero. A car can only hang from a ceiling once downforce matches its weight.
| Car | Mass | Downforce area ClA | Speed to drive on a ceiling |
|---|---|---|---|
| Formula 1 car (typical) | 800 kg | 4.2 m² | about 199 km/h (124 mph) |
| Track-focused supercar | 1,400 kg | 1.5 m² | about 440 km/h (273 mph) |
| Road sports car | 1,500 kg | 0.3 m² | about 1,019 km/h (633 mph): impossible |
Fan cars that already stuck to the road
The idea is over 50 years old. The 1970 Chaparral 2J used a snowmobile engine to spin two fans under a skirted floor, and the 1978 Brabham BT46B fan car won its only Formula 1 race before it was withdrawn. In April 2025 the McMurtry Spéirling, a small electric fan car rated at about 2,000 kg of suction, became the first car to drive upside down, on a rotating rig.
Can the Roadster fly? The thruster math
To leave the ground, thrust has to beat the car's weight: about 2,350 kgf for a 2,350 kg car. Cold-gas thrusters push compressed air out at high speed, but compressed air holds little energy. Its specific impulse is roughly 60 to 70 seconds, so each kilogram of air gives about 65 seconds of 1 kgf of thrust.
Assuming a 600-litre tank at 300 bar (Tesla has not given the pressure), it would hold about 214 kg of air, enough in theory for about 6 seconds of hovering. In practice it is less, because thrust drops as the tank empties. That is why the demonstration was a short hop over other cars, not a flight.
Frequently asked questions
Can a normal car drive upside down?
No. A road car makes very little downforce, so it would need more than 1,000 km/h before its wings could hold its weight. Only cars with fan suction, or race cars at high speed, come close.
How much downforce does an F1 car make?
Typically more than its own weight from around 200 km/h and several times its weight at top speed, which is why the classic claim is that an F1 car could drive on a tunnel ceiling at about 120 mph.
Why does fan suction work when the car is standing still?
The fans move air no matter how fast the car goes. Wings need air flowing over them, which only happens when the car is moving.
Are the Tesla figures official?
The 4,700 kg suction and up to 2 g come from Tesla's unveiling. The car's mass and the thruster tank pressure are not published, so the preset values here are estimates you can change.
