The Tesla Roadster's Thrusters Last Seconds. Refilling Takes Hours

The new Tesla Roadster can apparently launch itself into the air, pull a barrel roll, and reach 60 mph in under a second. But replenishing the gas powering its thrusters currently takes considerably longer than using it.

In Top Gear’s walkaround video, Tesla’s vice president of vehicle engineering, Lars Moravy, said filling the Thrust version’s tank from an external high-pressure nitrogen supply currently takes two to six hours. The plan is to bring that down to 30 minutes.

This applies to the Thrust version’s 200-liter tank, not the larger setup on the flying Rocket.

Tesla’s reservation site lists Performance, Thrust, and Rocket versions, all advertised with downforce-generating fans that improve grip. The Performance has no thrusters, but it does have trunk space. The limited-availability Thrust variant adds four rear-facing boosters supplied by a tank behind the passenger compartment, occupying space otherwise available for luggage.

The invite-only Rocket version gets the entire array of 10 thrusters, including those needed for takeoff and airborne maneuvers. Moravy confirmed that an additional 400-liter pressure vessel replaces the passenger seat, making it a single-seater with 600 liters of total tank capacity.

These are cold thrusters, which release pressurized gas instead of burning fuel. Sending air out the back pushes the car forward, adding acceleration without requiring the tires to put any more power down. The Rocket's additional nozzles provide lift and control its orientation in the air, as you can see in Tesla’s demonstration video.

It’s still unclear how owners will refill the Roadster's tank. In the Top Gear video, Moravy describes connecting the car to an external high-pressure nitrogen supply. That differs from Musk’s claim that the Roadster can replenish its own tanks with air without requiring a special propellant. The Top Gear interview was filmed before the reveal, so Moravy may be describing the current setup while Musk may be promising a future capability. 

The suction fans that add downforce even when the car is standing still work differently. They are electric and draw air from underneath the car to generate downforce and improve grip—or drive upside down—just like the McMurtry Spéirling. 

In the Roadster, those fans run on battery power and draw nothing from the thruster tanks. The Roadster’s extra grip therefore needn’t disappear when its compressed-air supply runs low. But Tesla still needs to explain how long it can perform its other tricks and how long it needs to recharge.