Cars · Lesson 12 of 15Advanced15 min read

Thrusters and Fans on the 2026 Roadster

Tesla’s new Roadster adds two things no road car has had: thrusters that push it with jets of compressed air, and fans that suck it onto the road. Here’s what was announced, what Tesla’s patent covers, and the physics of how both work, with simulators you can run yourself.

What Tesla showed on October 15, 2026

On the evening of October 15, 2026, Tesla showed its new Roadster in a livestream. It’s an electric sports car with two extras no road car has had before: cold-gas thrusters that push the car with jets of compressed air, and fans that suck the car down onto the road. Elon Musk said production should start in 2028. Tesla gave no prices. Reservations were $50,000 for the Performance version and $250,000 for the Thrust version, The Next Web reported.

Reporters watching the demonstration saw the car drive up a curved ramp and stay on it upside down, held by its fans. Thrusters then launched it off the ramp, flipped it and landed it. In another run it jumped over a row of Tesla vehicles. Tesla also showed a recorded run from 0 to 60 mph in 0.81 seconds. No one outside Tesla has checked that time yet.

Almost everything we know comes from Tesla or from reporters who watched, a day after the event. The table labels who said what. Treat the numbers as claims until independent testers measure them.

What was announced, and who said it (as of October 16, 2026)
Claim	Who says so	Reported by
Three versions. Performance: active aero and a “multi-mode suction system.” Thrust: adds rear thrusters. Rocket: adds thrusters around the body for upward and rotational movement; one seat; invite only.	Tesla	Electrek, Teslarati
0–60 mph in under 1.6 s (Performance), under 0.9 s (Thrust) and under 0.59 s (Rocket)	Tesla	Electrek, Teslarati
A recorded 0–60 mph run of 0.81 s	Tesla; not independently verified	The Next Web
10 thrusters fed by about 600 liters of compressed air; the tanks can be refilled	Lars Moravy, Tesla’s vice president of vehicle engineering	TechCrunch, via The Next Web
Carbon-fiber overwrapped pressure vessels (COPVs) fill “every usable void”; more gas means more “flight time”	Tesla	Electrek
The thrusters make four to five times the force the tires can handle	Tesla	Electrek, Teslarati
Running thrusters in air, not the vacuum of space, needed new hardware and controls	Tesla	Electrek
The thrusters were built with SpaceX engineers	Reporters’ account	The Next Web
Fans pull air from under the car and can hold it upside down, even when it’s stopped	Tesla	Electrek, Teslarati
The Rocket version is not approved for public roads	Tesla’s Roadster page	The Next Web, Electrek
Production starts in 2028	Elon Musk	The Next Web, Electrek
Tank pressure, thrust per thruster, how long they fire, the car’s weight	Not published	—

The patent covers the fans, not the thrusters

Many people remember that Tesla filed a patent for this car. It did, but for the fans, not the thrusters. U.S. Patent 12,377,920, “Adaptive vehicle aerodynamics for downforce,” was filed on April 29, 2025, and granted to Tesla on August 5, 2025. It describes fans in air passages that pull air out of a space under the car, with skirts that reach down to the ground to close that space off. Lower pressure underneath means the air above presses the car down harder.

The patent describes two modes. In one, every skirt is down and the central fans run, for the most downforce on smooth surfaces. In the other, mainly the side skirts are down and all the fans run, for rougher ground. Its example has four fans. It gives no pressures or forces, and it never mentions thrusters, compressed gas or flight; Electrek pointed that out when the patent appeared in August 2025.

We looked for a Tesla patent on the thrusters and didn’t find one in published patent records as of October 16, 2026.

What’s new in the car

Underneath, the Roadster is an electric car: a battery pack, motors and tires, like the ones in Lesson 11. On top of that come the tanks, valves, thrusters, fans and skirts. Switch the map to Roadster (2026) to see them. Tesla hasn’t published a parts layout, so where they sit in our drawing is a sketch.

Pick “Roadster (2026)” above the drawing. Point at a new part to see what it does; click to jump to its section of this lesson.

The new parts and what they do
Part	What it does	What Tesla has said
Compressed-air tanks (COPVs)	Carbon-fiber-wrapped pressure vessels hold the gas.	They fill “every usable void”; about 600 liters in all (Moravy).
Valves and gas lines	Carry gas from the tanks and open and close each thruster quickly.	Running in air needed new hardware and controls.
Thrusters	Nozzles turn stored pressure into a fast jet that pushes the car.	10 thrusters (Moravy); rear-facing on Thrust, all around the body on Rocket.
Suction fans	Pull air out from under the car to lower the pressure there.	They can hold the car upside down, even when it’s stopped.
Skirts	Seal the space under the car so outside air can’t rush back in.	Described in patent US 12,377,920.
Battery, motors and tires	Drive the car the rest of the time, like any electric car.	Over 300 miles of range.

Push gas back, and the car goes forward

A cold-gas thruster is a bottle of squeezed gas with a valve and a nozzle. Open the valve and gas rushes out of the nozzle. To throw that gas backward, the thruster has to push on it. Newton’s third law says the gas pushes back on the thruster just as hard, the other way. That push on the thruster, and so on the car, is the thrust. The Third Law chapter in the Science Lab lets you try the same idea with two skaters.

Momentum is mass times velocity. Each second the nozzle gives a mass ṁ (“m-dot”) of gas a speed v_e backward, so the gas gains ṁ·v_e of backward momentum every second, and the car gains the same amount forward. Force is the rate at which momentum changes, so the thrust is ṁ·v_e. If the gas still has extra pressure when it leaves, that pressure pushes too and adds a second term. NASA writes the rocket thrust equation like this:

F = ṁ·v_e + (p_e − p_a)·A_e thrust = mass flow × exit speed + (exit pressure − outside pressure) × exit area

Impulse: force over time

Push for a while and you give the car an impulse: the force added up over time, J = ∫F dt. Impulse equals the change in momentum, so a thruster that pushes hard for a short time can do the same job as a weaker one that pushes longer. The Momentum and Collisions chapter shows impulse with eggs and pillows.

The jet doesn’t push on the air behind the car or on the road. It pushes only on the gas it throws out. That’s why rockets work in the vacuum of space, and it’s the idea behind the Rocket Builder. One difference: a rocket carries a huge share of its weight as fuel, while the Roadster’s air is a small share of the car, so the rocket equation’s big mass change matters much less here.

How much air fits in the tanks

Gas pressure is the push of countless molecules hitting a wall. Squeeze more of them into the same space and they hit more often, so the pressure rises. For most gases in ordinary conditions, the ideal gas law ties it together: p·V = m·R·T. Here R is a constant for each gas (about 287 joules per kilogram per kelvin for air) and T is the temperature in kelvins. Gas in a Box lets you watch it happen with bouncing molecules.

Tesla hasn’t said how hard its tanks are pressurized. The table shows what 600 liters would hold at a few pressures. One bar is about the air pressure at sea level (one atmosphere is 1.013 bar).

Air in 600 liters at 20 °C (ideal-gas estimate; Tesla hasn’t published the pressure)
Tank pressure	Air inside	In the simulator
100 bar	about 71 kg
200 bar	about 143 kg
300 bar	about 214 kg	the starting guess
700 bar	about 499 kg	the top of the slider

Real gas at high pressure

At hundreds of bar, real air is harder to squeeze than the ideal gas law says, so a real tank holds a few to tens of percent less than these estimates. The gap grows with pressure. Even so, that’s a lot of air: at 300 bar, more than 200 kilograms. It gets used up as the thrusters fire, so the car gets a little lighter during a burn. The simulator counts that.

The nozzle: a speed limit at the throat

A thruster’s nozzle narrows to a throat, then widens into a bell. Gas speeds up as it squeezes through the narrowing. When the tank pressure is more than about 1.9 times the outside pressure (for air), the gas reaches the speed of sound right at the throat and can’t go any faster there. That’s called choked flow. Raising the tank pressure then doesn’t make the gas at the throat faster; it makes it denser, so more kilograms pass each second. NASA gives the choked mass flow as:

ṁ = A_*·p_t·√(γ ⁄ (R·T_t))·(2 ⁄ (γ+1))^{(γ+1)/(2(γ−1))} ≈ 0.0404·A_*·p_t ⁄ √T_t for air, in SI units

How fast the gas leaves

Here A_* is the throat area, p_t and T_t are the pressure and temperature in the tank, and γ (gamma) is 1.4 for air and nitrogen. Past the throat, the widening bell lets the gas keep expanding and speed up beyond the speed of sound. If the bell is just the right size, the gas leaves at the outside pressure, the pressure term in the thrust equation drops out, and the exit speed is:

v_e = √( 2γ⁄(γ−1) · R·T_t · [1 − (p_a ⁄ p_t)^(γ−1)/γ] )

A cold-gas thruster, with ideal-gas numbers for air starting at 300 bar (an assumed pressure). The gas is choked at the throat and keeps speeding up in the bell. Sources: NASA Glenn Research Center, “Rocket Thrust Equations” and “Mass Flow Choking.”

Checking the numbers

For air at 300 bar and 20 °C, that formula gives about 690 meters per second, roughly twice the speed of sound in room air. A plain hole with no bell lets the gas out at the speed of sound (about 310 m/s for the gas, which has cooled to about −29 °C at the throat) with pressure left over. That makes less thrust for the same flow, and you can compare the two in the simulator.

NASA lists cold-gas thrusters on small spacecraft at a specific impulse of 40 to 110 seconds. Specific impulse is the effective exhaust speed divided by g, so that’s about 400 to 1,100 m/s, and our estimate sits inside that range.

Why cold gas gets cold

“Cold gas” means nothing burns. A rocket engine burns fuel to make hot, fast gas. A cold-gas thruster only lets stored gas out. NASA describes cold-gas systems as simple and mature, with no combustion, and says most use inert, non-toxic gases such as nitrogen. The trade-off is a small total push for their size.

The gas does get cold, though, and that’s the first law of thermodynamics. The Science Lab’s Energy and the First Law chapter writes it as ΔU = Q − W: the change in a gas’s internal energy equals the heat added to it minus the work it does. When gas expands quickly, in the nozzle or in the emptying tank, there’s little time for heat to flow in, so Q is close to zero. The gas does work as it expands, so W is positive and ΔU is negative. For an ideal gas, less internal energy means a lower temperature. OpenStax puts it simply: in an adiabatic expansion, the gas does work and its temperature drops.

T₂ ⁄ T₁ = (p₂ ⁄ p₁)^(γ−1)/γ adiabatic expansion of an ideal gas (γ = 1.4 for air)

How cold?

The numbers get extreme. In the ideal model, air expanding from 300 bar and 20 °C all the way down to 1 bar would cool to about −215 °C. That’s colder than −196 °C, where nitrogen boils, so real air would start to turn liquid before it got there, and any water vapor in it turns to frost long before that. The gas left in the tank cools too as its pressure falls. In the simulator, a one-second burn from 300 bar takes the tank gas from 20 °C to about −9 °C.

WhySo is it a rocket?

In physics terms, yes: it moves by throwing mass backward, like a rocket. But nothing burns. There are no flames and no hot exhaust, and the “fuel” is air that can be pumped back in; Tesla says the tanks can be refilled. That’s why it’s called a cold-gas thruster.

Try it: the thruster simulator

Choose a mode and press Fire. Boost points the thrusters backward, Brake points them forward, and Hop points them at the ground. Watch the tank pressure and temperature fall as the gas runs out, and compare the thrust with the tires’ grip and with the car’s weight. Tesla hasn’t published the tank pressure, nozzle size or the car’s weight, so those start at our guesses: 300 bar, 16 mm nozzle throats and 1,900 kg.

An ideal-gas model of the thrusters, from the NASA and OpenStax equations above. It isn’t Tesla’s design: every number Tesla hasn’t published is a slider, and the notes under the graphs list the assumptions.

Beating the grip limit

An ordinary car speeds up, brakes and turns only by pushing on the road through its tires. Friction caps that push. The most a tire can push is about μ times the force pressing it onto the road, where μ (mu) is the coefficient of friction. On flat ground that force is the car’s weight, m·g, so:

F_max = μ·m·g so the best acceleration on tires alone is a = μ·g

Why thrust gets around it

OpenStax lists μ = 1.0 for rubber on dry concrete and 0.7 on wet concrete. With μ = 1, no motor can get a car from 0 to 60 mph on flat ground in less than about 2.7 seconds: 60 mph is 26.8 m/s, and 26.8 ÷ 9.8 ≈ 2.7. Grip is the limit, not power. Real tires and roads vary, which is why μ is a slider. Lesson 10 covers what tires do.

Thrust doesn’t go through the tires, so friction doesn’t cap it. The thrusters push on the car directly, and the tires can still push at their limit on top of that. Tesla says its thrusters make four to five times the force the tires can handle. If Tesla’s recorded 0.81-second run is right, the car averaged 26.8 ÷ 0.81 ≈ 33 m/s² of acceleration. That’s about 3.4 g, far more than the 1 g that a grip of μ = 1 allows.

Fans that pull the car down

Air at sea level presses on everything with about 101,000 pascals, which is 101,000 newtons on every square meter. We don’t notice because it pushes equally from all sides. The fans change that. They pull air out from under the car, and the skirts slow outside air from leaking back in, so the pressure under the floor drops a little. Now the air on top pushes down harder than the air underneath pushes up. The difference is downforce:

downforce = Δp × A pressure difference × sealed floor area

Looking at the car from the front. The fan lowers the pressure under the floor a little; the skirts keep outside air from rushing in; the full-pressure air above presses the car down. Based on the fans and skirts described in Tesla’s patent US 12,377,920.

How little it takes to hang upside down

Say the sealed area is 4 square meters and the car has a mass of 1,900 kg. Both are our guesses; Tesla hasn’t published either. The car’s weight is 1,900 × 9.8 ≈ 18,600 newtons. To hang from a ceiling, the downforce must beat that, so the pressure drop must be at least 18,600 ÷ 4 ≈ 4,700 pascals. That’s under 5% of the air’s pressure: a small drop over a big area. Driving upside down takes more, because the tires also need something to grip with.

Downforce also raises the grip limit on an ordinary road. Friction depends on how hard the tires are pressed down, so the most grip becomes μ·(m·g + downforce) while the mass the tires must move stays the same. A wing makes downforce too, but its force grows with the square of the speed and is close to zero when the car is slow. Fans make suction even when the car is parked, which is how Tesla says the Roadster can hold itself upside down while stopped.

Set the pressure drop, the sealed area and the car’s mass, then flip the car to see when it can hang from a ceiling. Tesla hasn’t published any of these numbers.

Air tank or battery?

Compressed air stores energy, but not much for its weight. The most work a tank of gas could ever do, if it expanded slowly enough to stay at room temperature, is p·V·ln(p ⁄ p_a) − (p − p_a)·V. For 600 liters at 300 bar that’s about 84 megajoules, or 23 kilowatt-hours, and a fast burst gets less, because the gas cools as it expands. Per kilogram of air, the best case is about 110 watt-hours, before counting the tanks. In 2020 the Department of Energy put electric-car battery cells at about 220 watt-hours per kilogram.

Most of what the air does deliver goes into the exhaust, not the car. The gas and the car get equal and opposite momentum, but kinetic energy is ½·m·v², and the exhaust moves far faster than the car, so it carries most of the energy away. That’s why the Roadster drives on its battery and motors and saves the thrusters for bursts. Tesla says more gas means more “flight time.” It hasn’t said how long that is.

What we still don’t know

The tank pressure, the gas, the thrust of each thruster, and how long they can fire. Tesla hasn’t published them.
The car’s weight, and how much the tanks and the air add to it.
Whether the 0.81-second run and the other times hold up in independent tests.
How the thrusters are controlled to flip the car and land it, and how the fan modes are used on the road.
Whether Tesla has applied for a patent on the thrusters. The patent we found covers the fans.
Which versions will be sold where. Tesla’s page says the Rocket version isn’t approved for public roads.

When Tesla or independent testers publish numbers, you can put them into the simulators above. Until then, any figure that isn’t in Tesla’s own statements is an estimate. Check what it assumes.

Check yourself

Tap an answer to check it, or open “Show the answer.”

What pushes a cold-gas thruster, and the car, forward?
Show the answer
The gas it throws backward pushes back on it. Newton’s third law: the thruster pushes the gas backward, so the gas pushes the thruster forward. Nothing burns, and the jet doesn’t need anything behind it to push on.
On flat ground with tire grip μ = 1, what is the best acceleration from the tires alone?
Show the answer
About 1 g. Friction caps the push at μ·m·g, so the acceleration can’t beat μ·g, about 9.8 m/s² when μ = 1, however strong the motor is.
Why does air get colder as it rushes out of a nozzle?
Show the answer
It does work as it expands and has no time to take in heat. With Q close to zero, ΔU = Q − W is negative when the gas does work. For an ideal gas, less internal energy means a lower temperature.
What does Tesla’s published patent US 12,377,920 describe?
Show the answer
Fans and skirts that lower the air pressure under the car. The patent, “Adaptive vehicle aerodynamics for downforce,” covers fans and skirts. It never mentions thrusters or flight.
A 1,900 kg car has 4 m² of sealed floor. About how big a pressure drop lets it hang from a ceiling?
Show the answer
About 5% of the air’s pressure. Its weight is about 18,600 N, and 18,600 N ÷ 4 m² ≈ 4,700 Pa, under 5% of the 101,000 Pa the air pushes with.

Go deeper

Science Lab: Newton’s Laws, Chapter 3: The Third Law Action and reaction with skaters, carts and a horse.
Science Lab: Newton’s Laws, Chapter 5: Momentum and Collisions Impulse and momentum, hands on.
Science Lab: Rocket Builder Thrust and the rocket equation, from the launch pad to orbit.
Science Lab: Gas in a Box Pressure, volume and temperature with moving molecules.
Science Lab: Thermodynamics, Chapter 2: Energy and the First Law Why expanding gas cools. It uses ΔU = Q − W, with W the work done by the gas.
Lesson 11: Hybrids and Electric Cars The electric car underneath.
Lesson 10: Wheels and Tires in Depth Where grip comes from.
NASA Glenn Research Center: Rocket Thrust Equations The thrust, mass flow and exit speed equations.
NASA Small Spacecraft Technology: In-Space Propulsion (cold gas systems) How cold-gas thrusters are used on spacecraft.
U.S. Patent 12,377,920: Adaptive vehicle aerodynamics for downforce Tesla’s fan and skirt patent, full text.
Physics Ladder: Newton’s Third Law Pairs Physics 1
Physics Ladder: Impulse and Change in Momentum Physics 1
Physics Ladder: Conservation of Momentum Physics 1
Physics Ladder: Static Friction Physics 1
Physics Ladder: Pressure Physical Science
Physics Ladder: The Ideal Gas Law Physics 2
Physics Ladder: The First Law of Thermodynamics Physics 2
Physics Ladder: Isobaric, Isochoric, Isothermal and Adiabatic Processes Physics 2
Physics Ladder: Impulse as an Integral Mechanics
Physics Ladder: The Rocket Equation Mechanics

Sources

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