News
How does Tesla ‘Ludicrous Speed’ work?
Following the announcement that Tesla will be releasing a ‘Ludicrous Speed’ upgrade for the dual-motor Model S P85D and upcoming Model X, the natural question emerged: How does Tesla Ludicrous Speed work?
How was Tesla able to extract more acceleration from the already ‘Insane'(ly) quick Model S P85D, and from the same battery back?
Model S P85D at Tesla’s Los Angeles Service Center
It’s important to first understand that the Model S uses an inverter to convert the transfer of electrons from Tesla’s direct current (DC) battery back to alternating current (AC) of the electric motor. Quoting an analogy provided by ExplainThatStuff, we learn that the electrons work like a line of ants, marching along with packets of electrical energy in the same way that ants carry leaves. The more ants we have, theoretically, the more packets of electrical energy we’ll have.
Citing our friends at TeslaTap, current flowing from the battery passes through a contactor which is a large switch controlled by an electromagnet under software control. The contactor connects the battery pack from connections outside the pack such as to the motor inverter, chargers, etc.
The algorithms within Tesla’s Firmware helps maintain constant torque by controlling the amount of current flowing through the contactors and to the electric motors. Ludicrous Speed adds a safety fuse and a new type of contactor that can safely sustain a current draw of 1,300 amps to 1,500 amps thereby allowing the electric motors to temporarily produce more power, and for a longer duration of time. End result? Mind-shattering acceleration to the tune of 0-60 mph in 2.8 seconds.
>>> RELATED: Specifications for Tesla Model S and Model X Ludicrous Speed
Tesla Motors Blog
While working on our goal of making the power train last a million miles, we came up with the idea for an advanced smart fuse for the battery. Instead of a standard fuse that just melts past a certain amperage, requiring a big gap between the normal operating current and max current, we developed a fuse with its own electronics and a tiny lithium-ion battery. It constantly monitors current at the millisecond level and is pyro-actuated to cut power with extreme precision and certainty.
That was combined with upgrading the main pack contactor to use inconel (a high temperature space-grade superalloy) instead of steel, so that it remains springy under the heat of heavy current. The net result is that we can safely increase the max pack output from 1300 to 1500 Amps.
In Pennsylvania, we got between 10 and 12 inches of snow over the weekend as a nasty Winter storm ripped through a large portion of the country, bringing snow to some areas and nasty ice storms to others.
I have had a Model Y Performance for the week courtesy of Tesla, which got the car to me last Monday. Today was my last full day with it before I take it back to my local showroom, and with all the accumulation on it, I decided to run a cool little experiment: How long would it take for Tesla’s Defrost feature to melt 8 inches of snow?
Tesla’s Defrost feature is one of the best and most underrated that the car has in its arsenal. While every car out there has a defrost setting, Tesla’s can be activated through the Smartphone App and is one of the better-performing systems in my opinion.
It has come in handy a lot through the Fall and Winter, helping clear up my windshield more efficiently while also clearing up more of the front glass than other cars I’ve owned.
The test was simple: don’t touch any of the ice or snow with my ice scraper, and let the car do all the work, no matter how long it took. Of course, it would be quicker to just clear the ice off manually, but I really wanted to see how long it would take.
Tesla Model Y heat pump takes on Model S resistive heating in defrosting showdown
Observations
I started this test at around 10:30 a.m. It was still pretty cloudy and cold out, and I knew the latter portion of the test would get some help from the Sun as it was expected to come out around noon, maybe a little bit after.
I cranked it up and set my iPhone up on a tripod, and activated the Time Lapse feature in the Camera settings.
The rest of the test was sitting and waiting.
It didn’t take long to see some difference. In fact, by the 20-minute mark, there was some notable melting of snow and ice along the sides of the windshield near the A Pillar.
However, this test was not one that was “efficient” in any manner; it took about three hours and 40 minutes to get the snow to a point where I would feel comfortable driving out in public. In no way would I do this normally; I simply wanted to see how it would do with a massive accumulation of snow.
It did well, but in the future, I’ll stick to clearing it off manually and using the Defrost setting for clearing up some ice before the gym in the morning.
Check out the video of the test below:
❄️ How long will it take for the Tesla Model Y Performance to defrost and melt ONE FOOT of snow after a blizzard?
Let’s find out: pic.twitter.com/Zmfeveap1x
— TESLARATI (@Teslarati) January 26, 2026
Tesla Robotaxi ride-hailing without a Safety Monitor is proving to be a difficult task, according to some riders who made the journey to Austin to attempt to ride in one of its vehicles that has zero supervision.
Last week, Tesla officially removed Safety Monitors from some — not all — of its Robotaxi vehicles in Austin, Texas, answering skeptics who said the vehicles still needed supervision to operate safely and efficiently.
BREAKING: Tesla launches public Robotaxi rides in Austin with no Safety Monitor
Tesla aimed to remove Safety Monitors before the end of 2025, and it did, but only to company employees. It made the move last week to open the rides to the public, just a couple of weeks late to its original goal, but the accomplishment was impressive, nonetheless.
However, the small number of Robotaxis that are operating without Safety Monitors has proven difficult to hail for a ride. David Moss, who has gained notoriety recently as the person who has traveled over 10,000 miles in his Tesla on Full Self-Driving v14 without any interventions, made it to Austin last week.
He has tried to get a ride in a Safety Monitor-less Robotaxi for the better part of four days, and after 38 attempts, he still has yet to grab one:
Wow just wow!
It’s 8:30PM, 29° out ice storm hailing & Tesla Robotaxi service has turned back on!
Waymo is offline & vast majority of humans are home in the storm
Ride 38 was still supervised but by far most impressive yet pic.twitter.com/1aUnJkcYm8
— David Moss (@DavidMoss) January 25, 2026
Tesla said last week that it was rolling out a controlled test of the Safety Monitor-less Robotaxis. Ashok Elluswamy, who heads the AI program at Tesla, confirmed that the company was “starting with a few unsupervised vehicles mixed in with the broader Robotaxi fleet with Safety Monitors,” and that “the ratio will increase over time.”
This is a good strategy that prioritizes safety and keeps the company’s controlled rollout at the forefront of the Robotaxi rollout.
However, it will be interesting to see how quickly the company can scale these completely monitor-less rides. It has proven to be extremely difficult to get one, but that is understandable considering only a handful of the cars in the entire Austin fleet are operating with no supervision within the vehicle.
Tesla has given its biggest hint that Full Self-Driving in Europe is imminent, as a new feature seems to show that the company is preparing for frequent border crossings.
Tesla owner and influencer BLKMDL3, also known as Zack, recently took his Tesla to the border of California and Mexico at Tijuana, and at the international crossing, Full Self-Driving showed an interesting message: “Upcoming country border — FSD (Supervised) will become unavailable.”
FSD now shows a new message when approaching an international border crossing.
Stayed engaged the whole way as we crossed the border and worked great in Mexico! pic.twitter.com/bDzyLnyq0g
— Zack (@BLKMDL3) January 26, 2026
Due to regulatory approvals, once a Tesla operating on Full Self-Driving enters a new country, it is required to comply with the laws and regulations that are applicable to that territory. Even if legal, it seems Tesla will shut off FSD temporarily, confirming it is in a location where operation is approved.
This is something that will be extremely important in Europe, as crossing borders there is like crossing states in the U.S.; it’s pretty frequent compared to life in America, Canada, and Mexico.
Tesla has been working to get FSD approved in Europe for several years, and it has been getting close to being able to offer it to owners on the continent. However, it is still working through a lot of the red tape that is necessary for European regulators to approve use of the system on their continent.
This feature seems to be one that would be extremely useful in Europe, considering the fact that crossing borders into other countries is much more frequent than here in the U.S., and would cater to an area where approvals would differ.
Tesla has been testing FSD in Spain, France, England, and other European countries, and plans to continue expanding this effort. European owners have been fighting for a very long time to utilize the functionality, but the red tape has been the biggest bottleneck in the process.
Tesla Europe builds momentum with expanding FSD demos and regional launches
Tesla operates Full Self-Driving in the United States, China, Canada, Mexico, Puerto Rico, Australia, New Zealand, and South Korea.
Tesla winter weather test: How long does it take to melt 8 inches of snow?
Tesla Robotaxi ride-hailing without a Safety Monitor proves to be difficult
