Tesla’s North American firmware 2026.38.5.12, first seen Nov. 4, was still rolling out Wednesday and continues Full Self-Driving (Supervised) v14.3.13 on HW4, also called AI4, Teslascope showed. Not a Tesla App’s published release notes for the same build list v14.3.13 for HW4 and FSD (Supervised) v14.3 Lite for HW3, and say this is “an updated version of FSD v14.3.13” whose notes “remain the same.”
Why it matters: The update does not introduce a new FSD version number. HW4 vehicles stay on v14.3.13, while HW3 vehicles remain on the lighter “Lite” branch that Tesla says is distilled from HW4’s v14 software. FSD (Supervised) still requires an attentive driver and “does not make your vehicle autonomous,” the notes say.
Teslascope labeled 2026.38.5.12 as “AI4 V14.3.13,” put its North American distribution at 23.3% as of Nov. 11, and counted 588 tracked installs, including additional installations on Wednesday. Its FSD breakdown still listed most HW3 v14.3 Lite distribution on the earlier 2026.38.5.11 build, which was also still rolling Wednesday in North America and Ukraine at 18.1%. Not a Tesla App’s connected-fleet snapshot for .12 was smaller, at 1,820 vehicles, or 14.8%, a different sample than Teslascope’s.
On HW4, the v14.3.13 notes include an upgraded reinforcement-learning training stage, a rewritten MLIR-based AI compiler and runtime that Tesla says yields 20% faster reaction time, a stronger vision encoder for rare and low-visibility scenes, and improved handling of emergency vehicles, school buses, traffic lights and parking. On HW3, the v14.3 Lite notes say the software “distilled the intelligence from HW4 V14 into HW3,” and add parking, unparking and reversing, Arrival Options (parking lot, street, driveway or pull-over) and Speed Profiles, including a more conservative “SLOTH” profile. Upcoming items listed for v14.3.13 include pothole avoidance and broader reasoning beyond destination handling.