I wish I could buy HW4 for my car. Why can't we buy it?
HW3 Users: Why can't we just buy a HW4 computer and cameras instead of waiting ?
- Thread starter Karoshi
- Start date
At the moment i would rather appreciate an Upgrade to my MCU so i can get all the new features that were introduced for AMD Vehicles 
Next update again brings an AMD only Feature (3D Buildings in Maps)
Next update again brings an AMD only Feature (3D Buildings in Maps) 
the reason we can't just switch from HW3 to AI4 has nothing to do with looks. the incompatibility is physical and electrical.
first the new AI4 cameras have a significantly higher resolution compared to HW3 (the old 1.2 megapixels vs. the new 5 megapixels). so that huge jump in data requires different camera protocols and a new, thicker wiring harness with different connectors and higher bandwidth capacity. so trying to replace this wiring harness would require dismantling the car's interior, making it an EXTREMELY difficult, multi-day service job. (kinda like disconnecting every nerve from your brain, replacing every single nerve in your whole body, then putting your brain back in, maybe it sounds easy but it is not)
second the AI4 and the newer AMD ryzen MCU are completely different than the HW3 and intel atom chips in the 2020 model. they have different form factors, run on different voltages (AI4 uses 16v system in certain areas where HW3 uses 12v), and they also require a different cooling system due to increased processing power. so these boards are not designed to just plug into the old car's chassis.
and third the 2025 MS has the full 2021 refresh interior, which moved controls from stalks to the steering wheel and added a rear screen and a new horizontal main display. all of these new features rely on the updated hw4 architecture and its complex internal networking. so it wouldn't a single part upgrade; it's an entire electronic system replacement that simply doesn't fit into the older car's frame and connection points.
TL;DR buying the new hardware wouldn't work because none of the parts would physically or electrically connect to the 2020 car without entirely rebuilding the car from the ground up, making the cost and labor unjustifiable. this is why they have just opted in for upgrading us who bought FSD on HW3. obviously this is TERRIBLE by design and they should have future proofed HW3 but now they will pay immensely for it.
first the new AI4 cameras have a significantly higher resolution compared to HW3 (the old 1.2 megapixels vs. the new 5 megapixels). so that huge jump in data requires different camera protocols and a new, thicker wiring harness with different connectors and higher bandwidth capacity. so trying to replace this wiring harness would require dismantling the car's interior, making it an EXTREMELY difficult, multi-day service job. (kinda like disconnecting every nerve from your brain, replacing every single nerve in your whole body, then putting your brain back in, maybe it sounds easy but it is not)
second the AI4 and the newer AMD ryzen MCU are completely different than the HW3 and intel atom chips in the 2020 model. they have different form factors, run on different voltages (AI4 uses 16v system in certain areas where HW3 uses 12v), and they also require a different cooling system due to increased processing power. so these boards are not designed to just plug into the old car's chassis.
and third the 2025 MS has the full 2021 refresh interior, which moved controls from stalks to the steering wheel and added a rear screen and a new horizontal main display. all of these new features rely on the updated hw4 architecture and its complex internal networking. so it wouldn't a single part upgrade; it's an entire electronic system replacement that simply doesn't fit into the older car's frame and connection points.
TL;DR buying the new hardware wouldn't work because none of the parts would physically or electrically connect to the 2020 car without entirely rebuilding the car from the ground up, making the cost and labor unjustifiable. this is why they have just opted in for upgrading us who bought FSD on HW3. obviously this is TERRIBLE by design and they should have future proofed HW3 but now they will pay immensely for it.
Yes, yes, yes, I was expecting that answer, but I really don't think it's like rewiring a human brain, you're stretching that a little. Tesla is a pretty good hardware company and I would imagine they have thought of this retrofit, I get that they DONT want to do it, but it could still be done. I agree progress should not stop, but the price of FSD on AMD HW4 is $8k, but FSD (with less capability) on HW is also $8k, that does not seem right. FSD on HW3 should be less.
you are right, i was stretching that.
i have participated in brain surgery and you would be correct, they are not the same at all. i was just trying to get the point across or give an example. however, it still would not be easy to do this process at all. yes, they could in theory, but who wants to really pay that much money to upgrade their HW3 car to AI4? parts, labor, and the time it would take to complete. i personally don't think it's worth it, but that might not be the case for everyone. and if you are willing to pay for it, you could trade in your car and use the money that you would use for an upgrade for a new car. that seems like a better deal to me, but once again, everyone has a different opinion.
i have participated in brain surgery and you would be correct, they are not the same at all. i was just trying to get the point across or give an example. however, it still would not be easy to do this process at all. yes, they could in theory, but who wants to really pay that much money to upgrade their HW3 car to AI4? parts, labor, and the time it would take to complete. i personally don't think it's worth it, but that might not be the case for everyone. and if you are willing to pay for it, you could trade in your car and use the money that you would use for an upgrade for a new car. that seems like a better deal to me, but once again, everyone has a different opinion.
Last edited:
Yeah I know, my wife just does not listen to me when i talk about this stuff, so I need a place to rant !!
I personally dont want to invest in a new car as long as autonomy is not solved and fsd is not even available in Europe, so i have no need for new computers. Although i would appreciate an upgrade for both my autopilot and mcu computer, i can only really use the mcu upgrade here in europe. Considering the problems with the harness and electrical stuff (12v and 16v architecture) my hopes arent that high. I rather buy a new tesla when Ai5 or even Ai6 is out (Maybe even new MCU after MCU-Z), when i have driven my car for several years. Because right now, the value of my car isnt depreciating that much as the most deprectiation happens in the first few years.
I feel your pain. There aren't a lot of places outside online forums where us Tesla owners can rant or vent our frustrations, however small they may be. Every time I try telling my wife something about an update or a minor frustration about how Tesla handles things, I get the typical node in agreement, but without actually understanding what I mean. Still love her though, lol!
I agree. I think HW3 is a special case, but at the same time, HW3 owners that fully purchased FSD were promised that their cars would be capable of unsupervised FSD. So I understand their frustrations. And being that they were promised that, I would hope that Tesla honors that agreement instead of HW3 owners needing to band together in a class action to get their hardware upgraded. However difficult it may be, that was the promise that was made, and it would definitely hold up in court if it does come to that.you are right, i was stretching that.
Furthermore, I agree as well that it is kind of ridiculous to be treating a car as a test platform for hardware versions. A car isn't really a cheap thing to be purchasing, and not everyone is willing to swap cars just to get something that they were promised or under the impression that their car would be capable of. With that said, I really hope that Tesla shifts directions and starts taking into consideration on how to make their car's hardware upgradable. I'm sure plenty of people would be more than willing to pay a small fee to upgrade their car instead of needing to buy an entirely new one. Sure, it may not be as much profit as someone purchasing an entirely new car, but it would certainly make customers a lot more loyal to the brand knowing that their cars aren't going to be outdated so quickly.
It's the same way I feel about the new rumored battery packs that they may soon be included in their cars, that increase their range by quite a lot. I'm sure some people would find it worthwhile (especially if they are on older cars where degradation has taken its toll) to purchase a new battery pack, especially if it meant adding range, even when compared to new. I understand that the connections and voltages and such may be different. But surely Tesla can manage something to make it backwards compatible.
HW3 guy here on my 2022 M3LR. Regardless of what transpires for those of us who purchased FSD outright, there is no way in hell I would ever buy an AI4 or 5 Tesla until the day they have truly been approved as unsupervised and HW is no longer a rate limiter. I would have to be sure that the car is redesigned to be future-proof. I'm not sure that is even possible. I have a bit under 2 years remaining on my loan. That's fine. I'll see where we are in 2 years. Likely, I'll even downgrade in the future as I'll hopefully be retired and not spending my retirement account on $60K cars.
Yeah they did actually promise that when i was purchasing the car. So maybe there is a possible joint complaint to go along with when all the HW3 owners get abandoned on the idea of unsupervised FSD by Tesla. Will definetly join if it comes this far and no Upgrade is offered
But who knows what will be in 2 or 3 years. I will see then.