Tesla has quietly made some significant modifications to its latest Hardware 4 (HW4/AI4) computer systems. The changes are likely being made to reduce production costs as the company prepares for more affordable electric vehicles, and for the introduction of AI5.
The changes, detailed by well-known Tesla software hacker and analyst Green (@greentheonly), show that the automaker is stripping away several components once considered standard.
According to green, Tesla has removed non-essential connectors from the AI4 units used in the new Model 3 “Highland” and Model Y “Juniper.” Tesla has also eliminated the onboard batteries that previously powered the real-time clock (RTC).
Tesla has also streamlined its wiring harnesses by eliminating thick copper ground wires that traditionally run to each unit. Instead, the company is now relying on the vehicle’s chassis for grounding.
The changes to streamline and reduce the costs association with AI4 are part of a larger hardware evolution at Tesla and happening with newer computers on the horizon. Work is already underway on AI5, with CEO Elon Musk recently saying he had completed a design review of the new chip, which will initially be manufactured by TSMC in Taiwan before production turns to the U.S.
Further down the road, AI6 is being developed and is slated for production at Samsung’s upcoming Texas plant, part of a $16.5 billion partnership between the two companies. Musk said that the AI6 platform could eventually take over from Project Dojo as Tesla’s primary training system, since it is designed to handle both inference and large-scale training tasks.
Got to check some new HW4 car computers from model3 highland/ modelY refresh up close (the ones with the bumper cam connector) and looks like Tesla is trying to cut costs hard.
— green (@greentheonly) September 27, 2025
All non-essential connectors are gone, all on-board batteries for RTC clocks (and their connectors) are…
