News
Performance Gains after P85D Ludicrous Mode Upgrade
TMC member thimel recently had the Ludicrous mode upgrade installed on his Model S P85D. He carefully measured the performance of his car before and after, and found that Ludicrous mode is worth about a half second to 60 mph and a noticeable increase in power at all speeds up to 80.
Just how much faster is the the P85D with Ludicrous Mode upgrade? According to Tesla Motors Club (TMC) member thimel, the performance gains are significant, to the tune of 19% more power above 30 mph and a drop in 0-60 time from 3.2 to 2.9 seconds. Quarter mile time also drops from an already quick 11.8 seconds to an astounding 11.5 seconds.
thimel carefully measured the performance of the P85D both before and after the Ludicrous Mode upgrade. The performance data was then meticulously charted and plotted, painting a clear picture of the performance differences from the $5,000 retrofit.
[Image source: thimel via TMC]
According to thimel’s post from the TMC forum, “I started the before Ludicrous tests early in the morning and had not driven the car for many hours, but had charged it that night. The ambient temperature in my garage that morning was 59 degrees and it was 50 degrees outside during the tests. I started with a 90% charge and by the time I was done the charge was 70%. Creep mode was off to help avoid a very slow start. Insane mode was on of course. Climate control was off.
“I drove a few miles before starting the first test but did nothing else to warm the battery. I drove 5 miles at moderate acceleration and speeds between acceleration passes. This was both to give a chance for things to cool down and to return me to the same starting point for each acceleration pass.data shows the Ludicrous mode upgrade it worth nearly a half second in the sprint to 60 mph and several more miles per hour at the end of the quarter mile. ”
Next he charted his power and speed against time and found power to range from 380 kW, before the Ludicrous upgrade, to 451 kW after the upgrade with the Max Battery Power setting on. The setting heats the Tesla battery to a higher temperature thereby reducing its impedance and increasing current to provide short term acceleration and performance gains.
The biggest boost in performance after the Ludicrous upgrade happens above 30 mph. Below that, performance is about the same. But with Ludicrous mode engaged, there is a sizable increase in available torque. Before the upgrade, lateral acceleration reaches approximately 1.15 g at 15 mph, then falls below 1 g after 25 mph. After the upgrade, lateral acceleration peaks at 1.1 g and continues to pull over 1 g until slightly past 30+ mph. Most notably, the acceleration is consistently above the pre-Ludicrous Mode upgrade all the way until 80 mph.
[Image source: thimel via TMC]
In his notes, thimel makes some interesting points. “Above 30 mph, ludicrous clearly has more power. This is seen directly with the PowerTools readout…..which shows the maximum power increased from 380 to 451 kW, a 19% increase and by the shorter times to achieve speeds above 30 mph. The max power measured from the battery was 451 kW. This compares to 458 kW that Pete90D measured on his P90DL. So the battery doesn’t make much of a difference. The 0-60 time I got of 2.89 is also nearly identical to that Pete90D got of 2.901.”
He ends his post with this conclusion: “The P85D with ludicrous upgrade is significantly faster than without. There is 19% more power above 30 mph, 0-60 time drops from 3.2 to 2.9 seconds and the quarter mile time drops from 11.8 to 11.5. So it was fast before and is faster now. You get about two-thirds of the improvement if you don’t heat the battery with max battery power.”
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
