Tesla HW3 Runs Smaller FSD Model Than AI4; Performance To Be Similar

By Karan Singh
Not a Tesla App

Yesterday we broke the news that Tesla has finally been able to add support for hardware 3 with FSD v12.5.1.4. The update is version 2024.26.15 and is currently being tested by Tesla employees.

Ashok Elluswamy, Tesla’s Autopilot director, commented on our article and gave additional insight into how Tesla was able to add support for HW3 and what they’re working on next. He confirmed that Tesla’s FSD team was able to achieve similar performance between AI4 and HW3 with FSD V12.5

Similar Performance, Smaller Model

One of the key points Ashok mentioned was that HW3’s FSD 12.5 release has similar, but not exactly the same performance as the AI4 release. This appears to be due to the smaller AI model for HW3, which has been compute-constrained by memory and speed limitations.

Of course, Ashok also tells us to mind the fact that the parameter counts and size of the AI model aren’t exactly everything. Hardware 3 still has the advantage of being the primary focus of Tesla’s FSD teams until the new Supercomputer Cluster at Giga Texas comes online. That, plus the tremendous reams of data that Tesla has acquired from Hardware 3 vehicles on the road today means that the current Hardware 3 version of FSD V12.5 is probably in a pretty good spot.

Larger Model Coming to HW3

It looks like the Tesla FSD team is working on emulating AI4 in Hardware 3 now, as there are some unique hardware-based operations supported on AI4, that aren’t supported on Hardware 3. Ashok says that in order for Tesla to support the larger model on HW3 they’ll need to implement these AI4’s hardware features with software on HW3. He confirms that Tesla is actively implementing and verifying these operations and they plan to support the larger FSD model on HW3 in the future.

Right now it sounds like Tesla is compressing the model, but still able to get close to the same FSD performance of AI4.

We’re looking forward to seeing FSD 12.5 hitting HW3 vehicles in the upcoming weeks if all goes well with initial employee testing.

Positive Future

One of the keys here is Ashok has focused on mentioning that the same FSD V12.5 model can run on both hardware platforms in the future. He noted that the performance was similar, but not the same. We’re not quite sure how big the difference is going to be just yet, but it looks to be negligible – especially from the positivity behind his post.

Ashok also doesn’t mention FSD V12.6 or future major iterations of FSD, but we aren’t worried. It sounds like Tesla is still committed to supporting HW3 in future iterations of FSD working, so it looks like it’ll be in a good spot for the foreseeable future.

A Look at the Tesla Cybertruck’s Crumple Zones [VIDEO]

By Karan Singh
Not a Tesla App

Tesla’s Cybertruck has officially earned a 5-Star Safety Rating from the NHTSA—an impressive achievement given the vehicle’s design. The achievement demonstrates Tesla’s engineering prowess. As one engineer points out, it wasn’t an easy feat.

Interestingly, the NHTSA only recently disclosed the results, despite the crash tests being completed a while ago. According to Lars Moravy, Tesla’s VP of Vehicle Engineering, the team had been aware of the 5-star rating for quite some time. While the reason for the delay remains unclear, now that the results are public, Tesla’s engineers can finally share how they achieved the rating.

Crumple Zones

Wes Morril, the Cybertruck’s Lead Engineer, wrote about the crash test video on X recently, addressing the claims that the Cybertruck doesn’t have a crumple zone. He also posted a side-by-side video (below) of the engineering analysis and the crash test itself.

Engineered Crash Safety

There’s a lot of engineering precision at play when a Cybertruck is involved in a crash. Unlike traditional crash structures that rely on crash cans and collapse points, the Cybertruck’s front gigacasting is designed to absorb and redirect impact forces in a highly controlled manner.

It all starts with the bumper beam, which crushes within the first few milliseconds of a high-speed impact. At the same time, the vehicle’s sensors rapidly analyze the crash dynamics and determine the optimal deployment of safety restraints, including airbags and seat belt pre-tensioners. These split-second actions are crucial in keeping occupants safe.

As the crash progresses, the vehicle’s structure deforms in a carefully engineered sequence. The drive unit cradle bends, directing the solid drive unit downward and out of the way, allowing the gigacasting to begin absorbing impact forces.

The casting crushes cell by cell, methodically dissipating energy in a controlled manner. This gradual deceleration reduces the g-forces transferred to occupants, making the crash much less severe. As the gigacast begins crushing, the safety restraints are deployed.

As Wes points out in his post - you can see how accurate the virtual analysis and modeling were. The video shows the simulated crash side by side with the real-life crash test and they’re almost identical. All that virtual testing helps provide feedback into the loop to design a better and safer system - one that is uniquely different than any other vehicle on the road.

Tesla Eliminates Front Casting on New Model Y; Improves Rear Casting

By Not a Tesla App Staff
Not a Tesla App

Tesla has pioneered the use of single-piece castings for the front and rear sections of their vehicles, thanks to its innovative Gigapress process. Many automakers are now following suit, as this approach allows the crash structure to be integrated directly into the casting.

This makes the castings not only safer but also easier to manufacture in a single step, reducing costs and improving repairability. For example, replacing the entire rear frame of a Cybertruck is estimated to cost under $10,000 USD, with most of the expense coming from labor, according to estimates shared on X after high-speed rear collisions.

These insights come from Sandy Munro’s interview (posted below) with Lars Moravy, Tesla’s VP of Vehicle Engineering, highlighting how these advancements contribute to the improvements in Tesla’s latest vehicles, including the New Model Y.

However, with the new Model Y, Tesla has decided to go a different route and eliminated the front gigacast.

No Front Casting

Tesla’s factories aren’t equipped to produce both front and rear castings for the Model Y. Only Giga Texas and Giga Berlin used structural battery packs, but these were quickly phased out due to the underwhelming performance of the first-generation 4680 battery.

Tesla has gone back to building a common body across the globe, increasing part interchangeability and reducing supply chain complexity across the four factories that produce the Model Y. They’ve instead improved and reduced the number of unique parts up front to help simplify assembly and repair.

There is still potential for Tesla to switch back to using a front and rear casting - especially with their innovative unboxed assembly method. However, that will also require Tesla to begin using a structural battery pack again, which could potentially happen in the future with new battery technology.

Rear Casting Improvements

The rear casting has been completely redesigned, shedding 7 kg (15.4 lbs) and cutting machining time in half. Originally weighing around 67 kg (147 lbs), the new casting is now approximately 60 kg (132 lbs).

This 15% weight reduction improves both vehicle dynamics and range while also increasing the rear structure’s stiffness, reducing body flex during maneuvers.

Tesla leveraged its in-house fluid dynamics software to optimize the design, resulting in castings that resemble organic structures in some areas and flowing river patterns in others. Additionally, manufacturing efficiency has dramatically improved—the casting process, which originally took 180 seconds per part, has been reduced to just 75 seconds, a nearly 60% time reduction per unit.

New Casting Methods

Tesla’s new casting method incorporates conformal cooling, which cools the die directly within the gigapress. Tesla has been refining the die-casting machines and collaborating with manufacturers to improve the gigapress process.

In 2023, Tesla patented a thermal control unit for the casting process. This system uses real-time temperature analysis and precise mixing of metal streams to optimize casting quality. SETI Park, which covers Tesla’s manufacturing patents on X, offers a great series for those interested in learning more.

The new system allows Tesla to control the flow of cooling liquid, precisely directing water to different parts of the die, cooling them at varying rates. This enables faster material flow and quicker cooling, improving both dimensional stability and the speed of removing the part from the press for the next stage.

With these new process improvements, Tesla now rolls out a new Model Y at Giga Berlin, Giga Texas, and Fremont every 43 seconds—an astounding achievement in auto manufacturing. Meanwhile, Giga Shanghai operates two Model Y lines, delivering a completed vehicle every 35 seconds.

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