Tesla‘s chief Elon Musk said in a series of posts on X after the Roadster’s unveiling that the car could reach about 400 mph and would be able to perform its stunts by itself, as Tesla shares gave up an early gain of more than 5% to close lower on Friday.
“I think we can reach a peak speed of >0.5 Mach or ~400 mph,” Musk wrote shortly after midnight Eastern Time on Saturday.
That is far above the more than 230 mph Tesla quotes for the Rocket version, the invite-only single-seater with thrusters around its body. Half the speed of sound at sea level is roughly 380 mph.
Musk was replying to Fox News host Jesse Watters, who had posted a clip of the car with the caption: “ELON MUSK JUST UNVEILED A FLYING CAR 🤯🤯 ROADSTER WITH 10 COLD-GAS THRUSTERS, HITS 230 MPH, AND GOES FROM ZERO TO 60 IN UNDER A SECOND!”
Tesla has not said how many thrusters the Rocket carries.
The company’s own engineers gave a lower figure the day before the event, in a video Top Gear filmed with VP of Vehicle Engineering Lars Moravy and Chief Designer Franz von Holzhausen.
“It’s uh 214 miles per hour for now, but we’re working on a version because the boss threw down the gauntlet there that you’ll have a 330 mph version of this car. It’s just gearing,” Tesla’s team told presenter Tom Ford.
Musk’s post on Saturday raised that ambition by approximately 70 mph.
A ‘Sentient’ Roadster
Musk’s most expansive claim came in a reply to a tech blogger.
“You aren’t actually driving the Roadster at all. You are driving a computer and it is telling another computer how to drive the car. It is steer by wire. Brake by wire. Accelerate by wire,” Scoble wrote hours after the event, quoting a video of it.
“True,” Musk replied on Saturday. “You will be able to ask the Roadster to perform any of the tricks shown autonomously, as it will be sentient,” he wrote.
“Also, we will have a wild looping track (crazier even than Hot Wheels) at our Texas HQ where you can test out your Roadster.”
The post had drawn more than 24,000 likes and about 3 million views by Saturday afternoon.
It sits uneasily with Tesla’s own pitch, which calls the car “the best of the last human-driven cars.”
Moravy described the brief in similar terms in the Top Gear video, after noting that Tesla’s Cybercab robotaxis were already on the roads of Austin.
“Really the task here was to make the last best driver’s car,” he said. “That’s kind of a mantra I’ve been holding for a while.”
The car does use steer-by-wire and brake-by-wire, as Scoble noted, and Tesla’s team told Top Gear the aim was a “super enjoyable” grand touring feel with linear responses from the steering, brakes and accelerator when the extra systems are not in use.
At the event at SpaceX‘s test site in McGregor, Texas, the Roadster drove up an inverted ramp and held itself there with suction fans, flipped, used thrusters to right itself and landed, and later jumped over a lineup of Tesla vehicles.
Tesla said production would begin in 2028, and the Rocket is listed as “Not approved for public road use.”
Musk did not say when the autonomous capability would be available or how it would be regulated.
Spider-Man and Sam Altman
Musk’s first post-event reply came while Tesla shares were already trading below Thursday’s close.
“The Roadster could fly, rotate and stick to the underside of an overpass like Spider-Man,” he wrote.
Musk was responding to Pierrick Chevallier, a visual-effects artist whose profile says he tests AI video, who had posted a 30-second computer-generated clip of a Roadster lifting off over a police roadblock on a city freeway.
The thrusters that would be needed for such stunts cannot be used on public roads, according to Tesla’s engineers.
“You’ll be able to drive with this on the road, but you can’t use the system on a road,” Tesla’s team told Top Gear, adding that the Rocket version would be for off-road use only.
The Thrust version stores nitrogen in a 200-liter carbon-overwrapped pressure vessel rated to about 10,000 pounds per square inch, Tesla’s team said.
A single fill lasts “about fiveish seconds” and can be used once, and refills currently take “two to six hours,” which Tesla hopes to cut to under half an hour, Moravy said.
Later on Friday, Musk turned to OpenAI Chief Executive Officer Sam Altman, who had praised the car: “Wow the new roadster looks quite amazing, good job @elonmusk.”
Another user asked Altman under that post, “Did you cancel your order cancellation,” and Musk replied: “Indeed.”
The jab refers to an October 2025 post in which Altman published his 2018 Roadster reservation, his request for a refund and a bounced email from Tesla, adding: “But 7.5 years has felt like a long time to wait.”
Musk responded at the time that Altman had received a refund “within 24 hours.”
Shares Give Back Their Gains
Tesla shares rose as much as 5.4% to $382.10 in premarket trading on Friday.
They opened at $369.15, peaked at $370.50, fell as low as $349.33 in the afternoon and closed down 2.1% at $354.72, on volume of 62.1 million shares, more than double Thursday’s.
The decline matched the wider technology market, with the Nasdaq Composite also falling 2.1%.
All four of Musk’s replies were posted after the stock had turned lower, three of them after the close.
JPMorgan analyst Rajat Gupta kept a ‘Neutral’ rating and a $415 price target on Tesla after the event, according to a note obtained by Price Target, which tracks the latest Wall Street analyst price targets, upgrades, downgrades and stock ratings.
Tesla “did not disclose final pricing, battery capacity, driving range or anticipated production volumes,” Gupta wrote.
The company’s team put real-world range at about 310 to 320 miles in the Top Gear video, published on Friday, against the 620 miles Tesla promised for the car in 2017, and Moravy said Tesla was aiming for a weight of under 1,700 kilograms (3,750 pounds).
Tesla’s engineers said the higher-performance versions would have more than 1,000 kilowatts from two motors on the rear axle, and that the battery could add charge at more than 500 kilowatts, with a target of 15% to 85% in 10 minutes.
Top Gear noted in the video’s description that some figures were updated after filming and that specifications for the base Roadster remain estimates.
Tesla is taking reservations of $50,000 for the Performance version and $250,000 for the Thrust version, and Musk had billed the event in advance as a candidate for the greatest product demo.
The company will report third-quarter results after the market closes on Wednesday, October 21.
