A recent episode of Sandy Munro’s Tesla Model Y teardown series has revealed that the electric car company utilized friction stir welding (FSW) for the crossover’s thermal management system. The welding technique is commonly used among aerospace companies, like SpaceX, as a way to maintain the strength of aluminum parts while securing a reliable bond between pieces.
Munro’s analysis of the Octovalve coolant system revealed Tesla’s techniques for the revised thermal management portion of the Model Y. Munro discovered the Octovalve on April 4 after digging into the Model Y’s internal build. The new coolant assembly seemed to be a revised version of the Model 3’s “Superbottle,” which served as the heart of the sedan’s thermal management system.
A car’s thermal management apparatus is responsible for controlling and maintaining proper temperatures in critical portions of the vehicle. In the case of the Model Y, the Octovalve is responsible for motor, battery, and cabin cooling, according to Munro. The Detroit auto veteran said that typically, these systems should not be cooling the cabin if they are controlling battery or motor temperature. The thermal management system in the Model Y seems to be controlling the cabin, the battery, the electronics, and the motor nonetheless.
The Octovalve seems to be a state-of-the-art system as it uses, “some clever little ball valves that open and close to make sure that everything’s getting heated or everything’s being cooled to where it needs to be,” Munro said.
With the assembly overlooking the temperature for these many parts of the vehicle, the system is subjected to drastic and sharp temperature changes. Over time, the difference between heat and cold can begin to weaken portions of the car part, especially if it was exposed to excessive temperatures during manufacturing. This is where some SpaceX-grade solutions come into play.
Tesla chose to utilize friction stir welding for its aluminum portions of the coolant assembly. “This is a cool way of putting two parts of aluminum together, some other materials as well, but aluminum is kind of the most suited for it. And in essence, what happens is you have a stylus that spins around very very quickly. It pokes through the two pieces of metal that you want to friction stir weld. Then, it goes around the outside edge, and what it does is it uses the plastic state or thixotropic state of the aluminum to bind it together,” Munro said.
Simply put, the process allows aluminum to reach a temperature that allows two pieces of metal to come together with a strong bond, but it never turns the metal into a soft, liquid-like state. “It’s like soft butter, butter that you could see is firm, but you could cut it with a knife.”
The advantage of using this process is that the heat from the welding process only applies to the outer edges of the metal. The additional material that is not bonded to anything does not see the heat and is not weakened by the welding process. Stir welding is also time effective as it can be completed in a short period, but it is a careful process that does not apply unneeded stress upon the rest of the assembly.
SpaceX uses friction stir welding for its rockets, as it increases strength by exposing only the bonded portions of two pieces of metal to each other. Friction stir welding was used by SpaceX back in 2008 when the company was combining barrel sections of the Falcon 9’s second stage. “The FSW joins metal without flames, sparking, inert gasses, or fumes, and produces a far superior weld in aluminum-lithium alloys as compared to traditional methods,” SpaceX said in a news update.
In the spirit of humor, Tesla and Elon Musk saw the Octovalve as a perfect opportunity to not only improve the performance of the vehicle temperature regulation system but also as an appropriate time to sprinkle in some additional humor in the form of an Easter Egg. The Model 3 donned a cape-wearing bottle-figured superhero for its “Superbottle” system, while the Model Y includes a snowflake-stamped Octopus as an Easter Egg.
Tesla has increased the effectiveness of its thermal management with the introduction of the Model Y’s Octovalve system. Elon Musk stated that it was some of the best engineering he had ever seen. The welding process could increase the longevity of the machine through its lack of exposure to excessive heat and stress during manufacturing.
Watch Munro’s video on the Model Y’s Octovalve welding below.
News
Tesla confirms that it finally solved its 4680 battery’s dry cathode process
The suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.
Tesla has confirmed that it is now producing both the anode and cathode of its 4680 battery cells using a dry-electrode process, marking a key breakthrough in a technology the company has been working to industrialize for years.
The update, disclosed in Tesla’s Q4 and FY 2025 update letter, suggests the company has finally resolved one of the most challenging aspects of its next-generation battery cells.
Dry cathode 4680 cells
In its Q4 and FY 2025 update letter, Tesla stated that it is now producing 4680 cells whose anode and cathode were produced during the dry electrode process. The confirmation addresses long-standing questions around whether Tesla could bring its dry cathode process into sustained production.
The disclosure was highlighted on X by Bonne Eggleston, Tesla’s Vice President of 4680 batteries, who wrote that “both electrodes use our dry process.”
Tesla first introduced the dry-electrode concept during its Battery Day presentation in 2020, pitching it as a way to simplify production, reduce factory footprint, lower costs, and improve energy density. While Tesla has been producing 4680 cells for some time, the company had previously relied on more conventional approaches for parts of the process, leading to questions about whether a full dry-electrode process could even be achieved.
4680 packs for Model Y
Tesla also revealed in its Q4 and FY 2025 Update Letter that it has begun producing battery packs for certain Model Y vehicles using its in-house 4680 cells. As per Tesla:
“We have begun to produce battery packs for certain Model Ys with our 4680 cells, unlocking an additional vector of supply to help navigate increasingly complex supply chain challenges caused by trade barriers and tariff risks.”
The timing is notable. With Tesla preparing to wind down Model S and Model X production, the Model Y and Model 3 are expected to account for an even larger share of the company’s vehicle output. Ensuring that the Model Y can be equipped with domestically produced 4680 battery packs gives Tesla greater flexibility to maintain production volumes in the United States, even as global battery supply chains face increasing complexity.
Elon Musk
Tesla Giga Texas to feature massive Optimus V4 production line
This suggests that while the first Optimus line will be set up in the Fremont Factory, the real ramp of Optimus’ production will happen in Giga Texas.
Tesla will build Optimus 4 in Giga Texas, and its production line will be massive. This was, at least, as per recent comments by CEO Elon Musk on social media platform X.
Optimus 4 production
In response to a post on X which expressed surprise that Optimus will be produced in California, Musk stated that “Optimus 4 will be built in Texas at much higher volume.” This suggests that while the first Optimus line will be set up in the Fremont Factory, and while the line itself will be capable of producing 1 million humanoid robots per year, the real ramp of Optimus’ production will happen in Giga Texas.
This was not the first time that Elon Musk shared his plans for Optimus’ production at Gigafactory Texas. During the 2025 Annual Shareholder Meeting, he stated that Giga Texas’ Optimus line will produce 10 million units of the humanoid robot per year. He did not, however, state at the time that Giga Texas would produce Optimus V4.
“So we’re going to launch on the fastest production ramp of any product of any large complex manufactured product ever, starting with building a one-million-unit production line in Fremont. And that’s Line one. And then a ten million unit per year production line here,” Musk stated.
How big Optimus could become
During Tesla’s Q4 and FY 2025 earnings call, Musk offered additional context on the potential of Optimus. While he stated that the ramp of Optimus’ production will be deliberate at first, the humanoid robot itself will have the potential to change the world.
“Optimus really will be a general-purpose robot that can learn by observing human behavior. You can demonstrate a task or verbally describe a task or show it a task. Even show it a video, it will be able to do that task. It’s going to be a very capable robot. I think long-term Optimus will have a very significant impact on the US GDP.
“It will actually move the needle on US GDP significantly. In conclusion, there are still many who doubt our ambitions for creating amazing abundance. We are confident it can be done, and we are making the right moves technologically to ensure that it does. Tesla, Inc. has never been a company to shy away from solving the hardest problems,” Musk stated.
Elon Musk
Rumored SpaceX-xAI merger gets apparent confirmation from Elon Musk
The comment follows reports that the rocket maker is weighing a transaction that could further consolidate Musk’s space and AI ventures.
Elon Musk appeared to confirm reports that SpaceX is exploring a potential merger with artificial intelligence startup xAI by responding positively to a post about the reported transaction on X.
Musk’s comment follows reports that the rocket maker is weighing a transaction that could further consolidate his space and AI ventures.
SpaceX xAI merger
As per a recent Reuters report, SpaceX has held discussions about merging with xAI, with the proposed structure potentially involving an exchange of xAI shares for SpaceX stock. The value, structure, and timing of any deal have not been finalized, and no agreement has been signed.
Musk appeared to acknowledge the report in a brief reply on X, responding “Yeah” to a post that described SpaceX as a future “Dyson Swarm company.” The comment references a Dyson Swarm, a sci-fi megastructure concept that consists of a massive network of satellites or structures that orbit a celestial body to harness its energy.
Reuters noted that two entities were formed in Nevada on January 21 to facilitate a potential transaction for the possible SpaceX-xAI merger. The discussions remain ongoing, and a transaction is not yet guaranteed, however.
AI and space infrastructure
A potential merger with xAI would align with Musk’s stated strategy of integrating artificial intelligence development with space-based systems. Musk has previously said that space-based infrastructure could support large-scale computing by leveraging continuous solar energy, an approach he has framed as economically scalable over time.
xAI already has operational ties to Musk’s other companies. The startup develops Grok, a large language model that holds a U.S. Department of Defense contract valued at up to $200 million. AI also plays a central role in SpaceX’s Starlink and Starshield satellite programs, which rely on automation and machine learning for network management and national security applications.
Musk has previously consolidated his businesses through share-based transactions, including Tesla’s acquisition of SolarCity in 2016 and xAI’s acquisition of X last year. Bloomberg has also claimed that Musk is considering a merger between SpaceX and Tesla in the future.
Tesla confirms that it finally solved its 4680 battery’s dry cathode process
Tesla Giga Texas to feature massive Optimus V4 production line
