Tesla Roadster’s five seconds of thrust require up to six hours of waiting
One of the new Tesla Roadster’s most outlandish technical features is also proving to be its biggest practical limitation. Compressed-nitrogen thrusters allow the car to accelerate to nearly 100 km/h in less than a second, but replenishing its five-second supply of thrust currently takes two to six hours. Tesla hopes to cut the wait to half an hour, but even that would make the technology more of a demonstration tool than an everyday performance boost.
690 bar of pressure and 200 litres of nitrogen
Tesla’s head of vehicle engineering, Lars Moravy, explained that the Thrust version of the Roadster uses a 200-litre nitrogen tank with an operating pressure of approximately 690 bar.
The system expels compressed gas through nozzles at high speed, generating thrust in the car’s direction of travel. Unlike a rocket engine, it involves no combustion, making these cold-gas thrusters.
According to Motor1, the tank empties in approximately five seconds. Refilling it requires specialist high-pressure equipment, as even many industrial nitrogen systems cannot reach the necessary pressure.
The Roadster’s thruster system therefore cannot be replenished at a conventional electric vehicle charging station. Tesla must develop a separate solution or provide owners with suitable refilling equipment.
Three versions, one of which can fly Tesla plans to put the second-generation Roadster, unveiled in October, into production in 2028.
The manufacturer plans three versions.
Performance: a two-seat electric sports car with active aerodynamics and a fan-assisted downforce system, but no thrusters. Thrust: a version with four rear cold-gas thrusters, intended to accelerate to 97 km/h in less than a second. Rocket: a single-seat special version with ten thrusters, capable of lifting itself into the air and changing its attitude while airborne.
The Rocket also uses a 400-litre gas tank. Tesla confirms that this version does not meet the requirements for use on public roads. Whether the Thrust will be road-legal also remains unresolved.
Impressive technology, questionable practical value
The Roadster’s cold-gas thrusters allow it to overcome the acceleration limits imposed by tyre grip. Because thrust acts independently of traction at the wheels, the car can accelerate harder than electric motors and tyres alone would allow.
The technology’s drawbacks, however, are its short operating time, high system pressure and complicated refilling process. The tanks and thrusters also add weight to the car.
Type approval and safety also raise questions for the European market. The high-speed gas jet could pose a danger to people behind the car, and the system must comply with pressure-vessel and vehicle safety requirements.
By comparison, the Rimac Nevera and other electric hypercars can deliver exceptional acceleration without a separate compressed-gas system. Although they do not achieve the sub-one-second acceleration time promised by Tesla, their performance is repeatable.
The Tesla Roadster’s thrusters demonstrate its engineers’ boldness, but also expose the technology’s contradiction. The car can exhaust its entire reserve of additional thrust in five seconds, while replenishing it currently takes up to six hours. Turning an impressive demonstration into practical sports car technology still requires substantial development work.
