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Tesla Semi with trailer showcases unearthly acceleration and sound in new sighting
Just like all of Tesla’s other offerings, the Semi is a very quick vehicle. Prior to the truck’s unveiling, Elon Musk noted in a TED Talk that the Semi would be a “very spry” truck that could be driven around like sports car.
Musk’s comments were eventually highlighted by the Semi’s specs, such as its 0-60 mph time of 5 seconds flat when launching without a trailer, as well as actual sightings of the vehicle accelerating like a high-performance sedan. Earlier this year, for one, the Semi was spotted performing a seemingly impromptu tire-shredding acceleration run while cruising on an area between Tesla’s Fremont factory and its Palo Alto headquarters.
The Semi has since been sighted in multiple states across the US, and during the company’s Q2 2018 earnings call, Jerome Guillen, the former head of Tesla’s truck programs who is now serving as the company’s President of Automotive, pointed out that the vehicle had already been improved since it was initially unveiled. The exact nature of these improvements remains to be seen, but if a video of the Semi captured earlier this month is any indication, it appears that the electric long-hauler has gotten even more daunting and impressive when it performs a full-speed acceleration run.
The Tesla Semi was sighted in Salt Lake City earlier this month, and not long after that, the truck visited the company’s office in Draper, UT. The vehicle attracted the attention of members of the Tesla community, including r/TeslaMotors subreddit member u/m3gusta_, who was able to capture the vehicle on video as it accelerated forward while hauling a trailer. The video was brief, but it was enough to show what the Semi looks and sounds like when it is launching with what seemed like the vehicle’s full power. Needless to say, the Tesla Semi’s quickness, as well as the unmistakable, high-pitched, futuristic sound of the truck’s four Model 3-derived electric motors, were nothing short of unearthly.
The Semi’s performance, handling, and power were specifically pointed out by professional driver Emile Bouret, a close friend of Tesla chief designer Franz von Holzhausen, in an Instagram post earlier this month. Bouret, who is no stranger to the power and performance of Tesla’s electric cars due to his work since the original Tesla Roadster (he also conducted the test drives in the next-gen Roadster during the Semi’s unveiling last year), noted that the Semi’s “speed and agility” were at odds with a vehicle of its size. Bouret further dubbed the electric long-hauler as a truck that is cool and crazy in equal measure.
Over the past month, sightings of the Semi have increased, with the vehicle being spotted traveling across several states and visiting some of its reservation holders like J.B. Hunt, UPS, and Ruan Transportation Management Systems. Tesla’s engineers accompanying the vehicle as it conducted its real-world tests have also begun sharing information about the truck to the Tesla community. During a stop in CO, for example, Tesla engineers shared details on the Semi’s upcoming sleeper cabin, the prototype’s carbon fiber construction, and the truck’s existing 26-camera system.
When the vehicle was unveiled last year, CEO Elon Musk noted that the Tesla Semi is expected to begin production sometime in 2019. As noted by Eric Markowitz & Dan Crowley of Worm Capital in a note published after a tour of Gigafactory 1, Tesla is planning on “earnestly” producing the Semi by 2020.
Watch the Tesla Semi launch with a trailer in the video below. Do note that this video is best viewed with the sound turned up.
https://streamable.com/vvkn6
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
Tesla AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla crosses major Unsupervised Self-Driving milestone
Tesla Robotaxi will be a 24/7 service: here’s when
