Tesla has reportedly begun a discreet rollout of its latest Full Self-Driving (FSD) computer version, dubbed “Hardware 4.5” or AI4.5. This change has come to light thanks to new Model Y owners taking delivery from the Fremont factory in late December and January, who have found their vehicles equipped with an Autopilot computer marked “AP4.5” or “AP45.” This identification aligns with a previously noted part number (2261336-02-A) in Tesla’s Electronic Parts Catalog that indicated an upcoming upgrade for the FSD computer.
Early confirmations emerged from owners like @Eric5un, who documented their experiences with the new front camera housing and the “AP45” label in their 2026 Model Y AWD Premium. Other owners have since reported similar discoveries, prompting interest from the Tesla hacking community and firmware analysts.
If confirmed, the new HW4.5 computer’s architecture might include a three-SoC (System-on-Chip) design, marking a substantial shift from the dual-SoC framework employed since the launch of the HW4 computer. Historically, Tesla’s FSD systems have utilized two identical chips for redundancy; the addition of a third chip could enhance computational power, provide greater redundancy, and serve as a bridge toward the anticipated AI5 chip.
The introduction of HW4.5 could serve to address a significant timeline gap: Tesla has delayed its much-touted AI5 chip until mid-2027, having originally promised delivery in late 2025. During this delay, Tesla now faces a pressing need for increased compute power in its vehicles. Thus, HW4.5 appears designed to ensure that new Model Y owners won’t find their vehicles obsolete when the AI5 finally arrives.
Newly delivered vehicles equipped with HW4.5 feature the updated 16-inch center display, another part of a broader “2026 model year” update. However, this shift raises questions for current owners of AI4 hardware as it echoes previous transitions in Tesla’s hardware history. CEO Elon Musk has stated that current AI4 hardware would be adequate for unsupervised FSD, but given the advancements in neural network requirements, doubts persist regarding the fulfillment of this promise.
Historically, Tesla has faced scrutiny over its commitment to delivering on self-driving capabilities, as fundamental claims about FSD systems have sometimes not materialized as advertised. With the introduction of HW4.5, Tesla is navigating an uneven landscape—it provides a solution to current demands while further complicating the situation for customers grappling with the uncertainties surrounding FSD’s capabilities.
In a growing trend of hardware changes made without official announcements, Tesla continues implementing improvements quietly, aiming to keep pace with the rapid advancements in its software technologies. Prospective Tesla buyers might find themselves receiving a vehicle with the newly released HW4.5, making it essential to verify specifications before finalizing any purchases. Overall, while the evolution of Tesla’s FSD technology demonstrates progress, potential customers are encouraged to focus on the current capabilities of the vehicles rather than future promises of autonomy.