Tesla Quietly Modifies HW4 (AI4) FSD Computer Hardware

Tesla’s relentless drive to optimize its manufacturing process is a core part of its corporate identity, and a look at the newest iterations of its FSD hardware proves that no component is safe from scrutiny. In a recent analysis of the AI4 (HW4) computer from recent Model 3 and Model Y vehicles, well-known Tesla hacker Green revealed a significantly leaner design. 

Green’s overall view is that Tesla is trying hard to cut costs, but there’s definitely a lot at play here, so let’s dig in.

Removing Components

According to Green’s findings, several components have been eliminated from the new computer boards and wiring harnesses as Tesla is eliminating all non-essential components of these boards. These include the removal of various connectors and even the small batteries that power the board’s real-time clocks.

The thick copper ground wire in the wiring harness has also been removed, and the board will presumably use the vehicle’s chassis as the ground, which is a standard practice.

From a purely component-level view, removing parts directly reduces the bill of materials and, consequently, the vehicle’s cost.

More Than Cost-Cutting

However, these changes represent more than simple cost-cutting. For instance, eliminating individual ground wires and instead using the vehicle’s chassis for 100% of the electrical grounding is a move that simplifies the entire design, reduces waste, and cuts costs simultaneously, while keeping the components grounded effectively.

That not only saves on copper but simplifies the wiring harness, making it lighter, less complex, and easier for robots to install during assembly.

Similarly, removing the small, individual RTC batteries suggests that Tesla may potentially rely on the vehicle’s low-voltage battery, further reducing the components that need to be sourced, installed, and that could potentially fail over time.

While the removal of non-essential connectors may raise concerns over limiting future retrofits and vehicle modifications, from a mass-manufacturing standpoint, every unused port represents an unnecessary cost.

This leaner AI4 computer is the same unit that now includes a front bumper connector, allowing owners to retrofit a front bumper camera in the future, potentially. Soon, new Model 3s are expected to come from the factory with the front bumper camera installed.

Why Now With AI5 Coming Soon?

While the evolution of HW4 is a prime example of Tesla’s approach to vehicle architecture that reduces costs and service, the timing is peculiar. AI5, Tesla’s next-gen FSD computer, is expected to enter mass production late next year, so it seems these improvements to HW4 will be short-lived. However, Tesla could be incorporating improvements they’re learning while developing AI5. Between now and next year, Tesla is expected to sell approximately 2 million vehicles, and these cost savings may be worthwhile, even if AI5 is many times more powerful and is just around the corner.

Tesla has officially activated its first 500kW Supercharger in Redwood City, California, a big moment for the company’s industry-leading charging infrastructure. With its advanced 800V high-voltage architecture, the Cybertruck is the first and currently only vehicle in Tesla’s fleet capable of harnessing this power.

However, as exciting as the headline number is, a detailed analysis reveals that the real-world impact for owners is more incremental than a leap. The true game-changer isn’t the charging speeds, but rather how much faster and easier it is to deploy Tesla’s new V4 cabinets that power these Superchargers.

First V4 cabinet Supercharger now live https://t.co/6T1X6MVTaj

0.5 MW, 3X power density, 2X stalls per cabinet

Higher throughput, higher efficiency, lower cost, faster deployments pic.twitter.com/5NbiABwgpy

— Tesla Charging (@TeslaCharging) September 29, 2025

How Much Faster Is It?

For a Cybertruck owner, the promise of 500kW charging paints a picture of dramatically shorter wait times, a big jump up from the already capable 325kW that only the Cybertruck, of all of Tesla’s vehicles, was capable of. It would help to cut down long stops while towing and shorten regular stops when road tripping.

Wes Morril, Cybertruck’s lead engineer, noted that the new V4 charger can help the truck recover up to 44% of its state of charge in just 15 minutes, which represents a respectable 13% improvement over the 250kW V3 stations.

The catch, however, is that this peak 500kW speed is just a fleeting benefit, only accessible when a driver arrives with a battery in the lowest single digits. For the vast majority of charging sessions that begin with a more typical 10-20% state of charge, the charge curve flattens considerably, and the advantage offered by the 500kW peak narrows. 

The total charge time to 80% is only about four minutes faster than a standard 250kW V3 Supercharger, and just three minutes faster than the more recent 325kW-capable V3.5 Superchargers. While any time saved is a win, this is more of an incremental improvement and not a revolutionary change, at least for now.

The Cybertrucks on the road today can recover up to 44% in 15 mins with V4 charger (13% faster than with V3)

For best results navigate to supercharger to initiate battery preconditioning and arrive at a low state of charge

— Wes (@wmorrill3) September 29, 2025

A Better Curve in the Future?

The advent of a 500kW Supercharger, while impressive on paper, currently appears to be a somewhat overstated achievement. The true efficacy of such a high-powered charger hinges not solely on its peak output but more critically on its ability to maintain high charging rates over a sustained period, effectively represented by the “area under the curve” of a charging profile. 

To truly unlock the benefits of this increased power, Tesla will need to demonstrate a willingness and capability to adjust the Cybertruck’s battery management system and associated charging algorithms. This adjustment would need to allow the vehicle to accept and store energy at a much faster average rate throughout the charging cycle. 

Without such optimizations, high peak power for a short period has little effect on charging times. It becomes more of a theoretical maximum than a practical advantage in real-world charging scenarios. 

Exclusive to Superchargers

Further tempering expectations is the fact that this capability is, for now, exclusive to the single 500kW Supercharger site—and within Tesla’s ecosystem. The Cybertruck’s software communicates a maximum power limit (EVMaximumPowerLimit) of 326kW to third-party chargers. According to the DIN/ISO charging standards, this is a hard limit that standards-compliant chargers will not exceed.

This means that even if an owner plugs into a third-party 500kW charger, the truck will still cap its intake at ~325kW. For the time being, unlocking the full potential is a perk reserved for Tesla’s latest Supercharger hardware.

The V4 Cabinet – The Real Game Changer

While the immediate benefit to drivers is modest at best, the technology enabling this new speed is the revolutionary part. The real story is Tesla’s new V4 Supercharger cabinet. According to Max de Zegher, Tesla’s Director of Charging, this unassuming white box is a masterpiece of efficiency, boasting three times the power density over the previous generation, while also being able to support twice the number of stalls per cabinet.

This leap in engineering has profound implications for the future of Tesla’s Supercharger network. Higher power density means more charging capacity can be installed in a smaller footprint, enabling more stalls in crowded urban centers. Supporting more stalls per cabinet also simplifies site layouts, lowers hardware costs, and dramatically speeds up the deployment of new stations.

Max went as far as to say that the V4 Cabinet will be the tech jump that will make 0.5MW charging for cars ubiquitous. This jump will hopefully enable the next generation of Tesla vehicles to charge at higher speeds, and not be limited to the Cybertruck.

This new cabinet also supports 1.2MW charging for the Semi, allowing Tesla to use the same cabinets for Superchargers and Megachargers.

The new cabinet is not only more powerful but also supports twice as many stalls as before. The V4 cabinet allows 500kW charging and supports up to eight stalls per cabinet. In comparison, a V3 cabinet supports 250kW charging on up to four stalls.

Ultimately, while the 500kW figure makes for a great headline, the immediate impact on the Cybertruck owner experience is more evolutionary than revolutionary. The true game-changer is the underlying V4 cabinet technology, which allows Tesla to scale its network faster and more efficiently than ever. The benefit today is a few minutes saved on a Cybertruck charge, but the long-term benefit is a more robust, capable, and future-proof charging network for everyone.

Tesla’s minimalist aesthetic is a core pillar of its brand identity, and nowhere is this more apparent than in its sleek, flush door handles across its entire lineup. This signature design element, however, is now under direct threat from regulators in one of Tesla’s most important markets: China.

China’s Ministry of Industry and Information Technology (MIIT) has released a draft of its new safety standards that specifically target concealed and electronic door handles, requiring Tesla to redesign its door handles.

The New Regulations

The proposed regulations are clear and comprehensive, addressing both exterior and interior handles. According to the draft, all vehicle doors must feature an external handle with a mechanical release. Crucially, in the event of an accident involving a battery fire, the doors on the non-collision side must be operable from the outside without power or tools.

The rules also specify that every door must have a mechanical release that is clearly visible, easy to find, and located within 300mm (about 12 inches) of the door’s edge. The goal is to ensure that first responders have clear and easy access to door handles during an emergency, without needing to be familiar with the wide variety of unique door handles on the market today — even in the event of a power failure.

What Tesla Needs to Change

These proposed rules aren’t a minor hurdle, especially for Tesla, which has unique, flush door handles across its entire lineup. The pop-out handles on the Model S, the button handles on the Model X, and the pivoting handles on the best-selling Model 3 and Model Y all rely on the vehicle’s electronic systems to actuate the latch.

While Tesla does include mechanical releases in the interior of the vehicle, often a lever located on the front doors and a cable pull for the rear, the new regulations raise questions on whether these backups are sufficiently easy to find. While Tesla has been trending in the right direction, it’s still far from ideal. In older Model 3s, the rear doors don’t include a mechanical release cable at all. While newer models feature a cable that can be pulled after removing a speaker grill or lifting a cover in the door pocket, they’re hardly ideal in an emergency situation.

The mechanical release for the front doors is more obvious. However, it’s still located in a different spot from the electronic button, which could potentially lead to confusion for passengers unfamiliar with the vehicle.

Externally, the challenge is similar, as there isn’t a way to open any of the doors from the outside without power. The windows in newer vehicles also feature laminated glass, which is great for noise isolation, but makes it much harder for someone to break through a window to access the interior handles.

Tesla’s Head of Design, Franz von Holzhausen, recently spoke about the upcoming Chinese regulations and how Tesla is working on redesigning its interior and exterior door handles to meet these new requirements. During the interview, Franz stated that Tesla’s teams are looking to combine the electronic and manual door-release mechanisms into a single button or lever. The goal is to make the handles more intuitive for occupants, so that if the electronic button fails to open the door, the mechanical release can be triggered by presumably pressing the button or handle harder. We recently took a look at a potential new design.

For the first time in Tesla’s history, the company may settle on a single door handle design across its lineup. The iconic door handles of the Model S will likely be gone, but hopefully, Tesla will come up with a new design that is both sleek and safety-focused.

The Push from Regulators

This regulatory push from China can be seen as a formalization of complaints and concerns that have followed Tesla’s designs for years. Owners in cold climates have long reported issues with handles freezing shut, and the reliance on electronics has always been a point of contention for safety advocates. This move may be the catalyst that forces the automaker to implement a solution.

With China being a market Tesla can’t afford to ignore, the company is at a crossroads. It faces the choice of developing a costly, market-specific design that abandons its signature look, or fast-tracking a new global door handle design that meets the world’s increasingly stringent safety standards. 

Whichever path it chooses, the era of the purely electronic, flush door handle may be drawing to a close.