In early 2023, Tesla launched its FSD Hardware 4.0 – now known as AI4 – an improved version of Hardware 3 with various advantages. This hardware launch initially came off to a rocky start with FSD and Autopilot not being available to freshly delivered vehicles.
Today though, AI4 is the next step as Tesla strides towards full autonomy. While Tesla hasn’t abandoned HW3 or declared it as legacy yet – and doesn’t seem to plan to, it’s still important to be able to figure out what hardware your vehicle has. This is especially true for those who have paid for, or are subscribed to FSD – as it seems that going forward, AI4 will receive major FSD updates before hardware 3, which will require optimization.
So, let’s go over what AI4 offers in terms of improvement, the fact that there is no retrofit path from Hardware 3, and finally, a few easy ways to tell FSD Hardware 3 from Hardware 4/ AI4.
HW4 / AI4 Improvements
AI4 brought along several improvements, including new cameras, new electrical and wiring harnesses, and most of all – improved processing power.
The new cameras bring improved resolution for better details. The rear camera on AI4 has a resolution of 1448x938 vs 1280x960 on Hardware 3. However, there’s a much larger differences in the front cameras. HW4/AI4 has a resolution of 2896x1876 while HW3 has a resolution of 1280x960. That’s a huge improvement in quality - additionally, that telltale red tint that they have ensures better performance in low-light conditions. The video below compares the difference between HW3 vs HW4.
Musk previously said that HW4 is about 3-5x faster than hardware 3, although all of that compute power isn’t being utilized yet. We’ll likely see the full power of HW4 come into play with the divergence of HW4 later this year.
How to Tell If You Have HW3 or HW4 / AI4
If you have access to the inside of the vehicle, the easiest and surefire way of determining the FSD hardware of a Tesla is to check in settings. As of software update 2024.38, Tesla has added the ability to view the vehicle’s hardware version. To see simply go to Settings > Software and then tap Additional Vehicle Information.
In the list of options, you’ll see ‘Autopilot computer’, followed by the FSD computer hardware version. You’ll likely see version 2.5, 3 or 4.
If You Don’t Have Access to the Vehicle
You should still be able to tell what version of the FSD computer is in the vehicle even if you don’t have access to the inside of the car. There are a few several ways to tell if you have Hardware 3, or HW4.
Delivery Date
The first is based on your model and delivery date. If you purchased Model S or X, you’ll likely have AI4 if you purchased after March 2023. If you have a Model Y, it’s after late May 2023 for vehicles made in the United States. The updated 2024 Model 3 has HW4, but if you have a 2017-2023 Model 3, you’ll have Hardware 3.
Red Camera Lenses
Next, if you’re not sure of the delivery date of your vehicle, or want to confirm, take a look at the vehicle itself. HW4/AI4 has cameras with red lenses – the easiest place to see this is on the front cameras – where there will be 2 red lenses and one black (fake) lens. AI4 got rid of the 3rd front-facing camera since the cameras now have a higher resolution.
The repeater cameras are also slightly different, with the same red tint, but include a smaller and narrower turn indicator.
No Retrofit to HW4
Elon Musk and Tesla have confirmed that unlike AP 2.5 or AP 2, Tesla does not intend to offer a retrofit for older vehicles. This isn’t a surprising move, especially given the fact that there is an entirely new wiring and cooling harness for the compute unit in AI4.
This, in turn, with AI4’s different form factor, means that upgrading HW3 vehicles to AI4 isn't feasible. A retrofit would be a complex and expensive task that would likely require building a custom solution that would fit into HW3 vehicles. It also comes with other complications, such as overwhelming Tesla Service. Instead, Tesla will continue to do it the software way – by optimizing and updating the FSD models to perform well on Hardware 3.
