Can Older Teslas Upgrade to HW4? Here’s the Real Story From Owners Who Tried
If you own an early Model 3 or Model Y, you’ve probably wondered the same thing as everyone else on Reddit and Facebook groups:
“Can I upgrade my car to HW4?”
There’s a lot of confusion online, so here’s a clean, honest breakdown based on real owner experiences, community reports, and official information.
1. Is There an Official Tesla HW4 Upgrade?
Not right now.
Unlike the old HW2 → HW3 upgrade program, Tesla has not announced a universal path for older vehicles to switch to HW4 — even if you’re willing to pay.
- Service centers currently do not offer HW4 upgrades
- There’s no pricing, no appointment option, and no official policy
- Tesla’s support pages only list software-based upgrades (FSD, acceleration boost, infotainment), not a full hardware swap
So if you’re waiting for Tesla to call and offer HW4 installation, it’s unlikely to happen anytime soon.
2. The Community Workaround: Third-Party HW4 Retrofits
Yes — it has been done.
And yes — it’s complicated.
Some owners in the U.S. and Europe have swapped HW3 to HW4 using parts from salvage cars or private sellers.
What’s required?
- HW4 computer
- Full HW4 camera set
- New wiring harnesses and brackets
- On some models: radar mount and power components
- Labor for disassembly, camera alignment, software pairing
Cost range:
$2,000 – $5,000 USD, depending on parts and labor.
Why it’s difficult:
It’s not a simple plug-and-play computer swap. HW4 changes the entire vision system:
- Cameras are in different positions
- Connectors are different
- Software must recognize and authorize hardware
Many owners describe the process as “half the car taken apart.”
3. The Biggest Risk: Software & FSD Compatibility
This is where most retrofits struggle.
Even with hardware installed:
- The computer must run the right firmware
- Cameras must calibrate correctly
- OTA updates may fail
- FSD may not activate or transfer
- Some cars work for a while, then break after an update
Real-world reports range from “everything works perfectly” to “lost FSD and can’t roll back.”
So yes — HW4 retrofits technically work. But they’re risky and absolutely not guaranteed.
4. Buying a Car That Already Has HW4
A surprisingly smart workaround has appeared:
Some dealerships and private sellers now offer used Model 3/Y units already retrofitted with HW4 and tested before sale.
Pros:
- No installation hassle
- No guessing about compatibility
- You see the car working before you buy
Cons:
- Price markup
- Still not officially supported by Tesla
If someone really wants HW4, this is often the safest “unofficial” option.
5. Is HW4 Worth All That Effort?
In daily use, here’s what owners report:
Improvements
- Cleaner, sharper, brighter cameras
- Much better night vision
- Smoother FSD decisions
- Better long-range object detection
- More computing horsepower for future updates
Limitations
- Many features are not fully unlocked yet
- Short-term FSD experience is similar on HW3 and HW4
- Tesla continues to release HW3 updates, so you’re not “left behind”
Bottom line:
HW4 is better — but not so much better that most owners should tear their cars apart for it.
6. So What Should Older Tesla Owners Do?
If you’re a normal driver:
Keep HW3. It still supports FSD, still gets OTA updates, and still works.
If you’re a hardcore FSD enthusiast who loves risk and DIY:
Find a proven retrofit shop with successful case studies, and confirm:
- FSD remains active
- OTA updates still work
- VIN is properly paired
- Warranty implications
If you just want HW4 the easy way:
Buy a new Tesla or a used one that already has HW4 installed.
Final Thought
HW4 is real, faster, cleaner, and more future-proof.
But for most owners, the smartest move is simple:
Drive the car you have — or upgrade to a new one — instead of trying to “Frankenstein” your old hardware.
At least until Tesla officially supports a factory upgrade path.
