Tesla began rolling out software 2026.26.6.5 on August 26, bundling FSD (Supervised) v14.3.8 with the long-delayed Summer Update. Here’s what actually changed, and who gets it.
It’s a Hardware 4 release — Hardware 3 gets something different
Per Tesla’s official release notes, FSD v14.3.8 is built for Hardware 4 cars (recent Model S, 3, X, Y, and Cybertruck). Tesla says the update upgrades the reinforcement-learning stage of the FSD neural network, rewrites the AI compiler for roughly 20% faster reaction time, and improves parking-spot selection and traffic-light handling at complex intersections. Hardware 3 cars are not getting v14.3.8 — instead they’re getting a separate, distilled version called FSD v14.1 Lite, with a more limited feature set. If you’re not sure which hardware your car has, check your software version screen before assuming either update applies to you; Tesla’s staged rollouts mean it can take days to weeks to reach every eligible car even within the same hardware tier.
The Summer Update lands for everyone
Separate from FSD, the Summer Update portion reaches all supported models and adds Grok voice commands, Automatic Navigation that adapts to routes you drive often, three new traction control modes, and an estimated range figure that now factors in battery aging over time. The new traction control modes are worth knowing by name if you drive somewhere that gets real weather: Auto handles normal conditions, Slippery Surface is meant for icy or wet roads, and Stuck Assist is built for snow, mud, or sand — the car resets to Auto every time you start a new drive, so it’s not something you have to remember to switch back.
Dirty Tesla put the update through a first drive the day it started rolling out:
That’s one driver’s real-world impressions on release day — treat it as a demo, not a guarantee of how the update will behave in your car, especially since Tesla’s staged rollout means your own vehicle may be running an earlier version like FSD 14.3.7 for a while yet. For what’s actually changed and for which hardware, the release notes linked above are the source to check.
