Tesla appears to be quietly rolling out a new iteration of its Full Self-Driving computer, with early buyers of newly delivered Model Y vehicles spotting Autopilot Hardware 4.5 (HW4.5 or AI4.5, as it’s being called in the wild).
Owners taking delivery of Fremont-built Model Y vehicles in late December and January have discovered their cars are equipped with a computer labeled “AP4.5” or “AP45,” matching a previously spotted entry in Tesla’s parts catalog for a new FSD computer. One of the first public confirmations came from Model Y Performance owner Jeremiah Jones (@jeremiahjones), who shared that his December 26 delivery included the new hardware.
The sightings have quickly caught the attention of the Tesla community, particularly well-known software sleuth and code-miner @greentheonly. Based on firmware clues, the new HW4.5 computer may feature a three-SoC design, potentially adding redundancy or safety improvements similar to Tesla’s quiet jump from HW2.0 to HW2.5 years ago. While no teardowns have yet confirmed processing gains, the design hints at an incremental but meaningful step forward.
Several of the newly delivered vehicles with HW4.5 also include Tesla’s updated 16-inch center display and revised windshield camera housing. However, they notably lack the repeater and rear camera washers that have recently appeared on Tesla’s dedicated Austin Robotaxi fleet, suggesting HW4.5 is being deployed broadly rather than exclusively for autonomous ride-hailing.
The timing is particularly interesting. AI4.5 appears to be a stopgap as Tesla finalizes its long-awaited AI5 chip, which Elon Musk recently said is “almost done.” AI5 is expected to offer a massive performance leap and is slated to enter early production later this year, with installation in consumer vehicles following in 2027. For now, it remains unclear what specifically necessitated the move from AI4 to AI4.5, especially as Musk has reiterated that current-generation AI4 hardware will be capable of handling Unsupervised FSD once it’s ready.
That uncertainty has left some owners uneasy. While Tesla has long maintained that HW3 vehicles will need upgrades to access the full scope of future FSD features, the emergence of HW4.5 raises new questions about long-term support for HW4 vehicles as Tesla continues to push its autonomy ambitions forward.
