Tesla’s latest Full Self-Driving (FSD) computer appears to have quietly entered production. A newly listed “Hardware 4.5” FSD computer was spotted in Tesla’s Parts Catalog over the weekend and has already been spotted in at least one newly delivered Model Y built at the Fremont factory.
The part in question was officially listed as “CAR COMPUTER – LEFT HAND DRIVE – PROVISIONED – HARDWARE 4.5,” carrying part number 2261336-S2-A and priced at US$2,300. That puts it just US$500 above the HW3.2 computer, a difference that suggests the updated hardware is intended as a quiet, rolling replacement on the production line rather than a standalone launch of an entirely new product.
Is this @telsa "Hardware 4.5" FSD computer new? I don't remember seeing it before @greentheonly Do you know anything about this? @SawyerMerritt @niccruzpatane pic.twitter.com/CFvwE1GpG8
— Todd DeRego (@toddderego) January 21, 2026
We use the word “was” because shortly after the information appeared in a post on X, Tesla updated its catalog to remove any reference to Hardware 4.5. However, the cat was already out of the bag. A new owner, Eric, who recently took delivery of a Model Y manufactured on January 22 in Fremont, dug into the vehicle and confirmed it was equipped with the new computer.
Internally, the hardware is labeled “AP45,” aligning with references that have existed in Tesla’s firmware for some time, according to well-known hacker @greentheonly on X.
Eric also confirmed the vehicle was equipped with several other recent changes, including a redesigned front camera housing that may be part of Tesla’s push to make the front camera easier to keep clean — an area Elon Musk previously described as a “major focus” — as well as a larger 16-inch center display.
The most interesting aspect of HW4.5 is what may be happening under the hood. Green has pointed out that Tesla’s software has referenced a three–system-on-chip (SoC) configuration for quite some time. Historically, Tesla’s FSD computers have relied on two compute nodes for redundancy, from HW3 through various HW4 revisions. However, traces of a third compute node have appeared in firmware over multiple 4.x releases, gradually becoming more prominent, and while green has yet to get his hands on one of these new computers for a tear down, he suggests this could be one of the major upgrades.
If Hardware 4.5 does indeed mark the shift to a three-SoC design, it would represent a meaningful step forward rather than a cosmetic revision and one that could allow Tesla to run larger neural networks that power its FSD software.
However, HW4.5 is merely a steppingstone to Tesla’s next-gen computer, referred to as AI5. According to Elon Musk, AI5 is nearing the final stages of its design and is expected to arrive later this year, with volume deployment targeted around 2027. Hardware 4.5 could fill the gap until then, ensuring vehicles built in the meantime are better equipped to handle increasingly demanding FSD software.
