Image: Tesla
Tesla has officially put an end to days of speculation about a mysterious “Hardware 4.5” upgrade appearing in new Model Y vehicles, attributing the sightings to a simple labeling mix-up.
The clarification came late Wednesday, January 28, 2026, via prominent Tesla news aggregator Sawyer Merritt. He reported that Tesla has begun reaching out to customers through sales advisors to confirm that the “AP45” markings found on some Autopilot computers do not represent new hardware.
“Tesla has started informing customers (through sales advisors) that there was a mislabeling of ‘AP45’, meaning there is currently no HW4.5,” Merritt shared on X. “All vehicles delivered today have AI4 (HW4). Tesla will update all labels, etc, to eliminate any confusion moving forward. Everyone can stop freaking out lol.”
The mystery began when 2026 Model Y owners in Fremont and Austin noticed “AP45” stickers on their Autopilot units and found matching “Hardware 4.5” references in Tesla’s official Electronic Parts Catalog (EPC). Many enthusiasts speculated this was a quiet hardware refresh—potentially featuring a new three-chip architecture—meant to serve as a “bridge” before the launch of Tesla’s next-generation AI5 (formerly HW5) processor.
However, Tesla’s internal stance is that the designation was a “temporary formatting error between manufacturing teams.” Following the buzz, Tesla quietly removed all references to HW4.5 from its public parts catalog, reverting the listings to standard HW4 components.
The news follows Tesla’s Q4 2025 earnings call, where executives including VP of Vehicle Engineering Lars Moravy emphasized the strength of the current fleet. Moravy noted that Tesla has a significant advantage in “manufacturing and scale,” with millions of vehicles already equipped with the AI4 (HW4) hardware necessary for autonomous progress.
During the same call, CEO Elon Musk confirmed that while the design for the much-anticipated AI5 is “almost done,” volume production is not expected until mid-2027.
For now, Tesla’s message is clear: despite the “4.5” stickers, new buyers are receiving the standard, proven Hardware 4 system. The company has committed to updating all labels to prevent further confusion.