Elon Musk has finally admitted that Teslas will never be able drive themselves.

Elon Musk has been promising a self-driving update to existing Teslas for the past five years. Now, the Tesla CEO is changing his tune dramatically. It's possible that it won't happen after all.

Musk dropped a bombshell in a conference call (via Electrek), when he said that "there's a chance that HW3 doesn't achieve the safety level which allows for FSD to be unsupervised."

To decode that statement, "HW3", refers to the self driving computer that Tesla began installing in its models starting in 2019, while "FSD", refers Full Self Driving which is a broad term for what's commonly known as Level 4 or 5 autonomous driving.

Level 4 allows for fully autonomous driving in a geo-fenced area. You'll need a driver and controls on board. Level 5 is the ultimate in autonomous driving, allowing you to go anywhere without a driver or steering wheel.

Musk has been promising a "FSD" upgrade for Teslas equipped with HW3 for years. Now he says that this may not be the case. Musk has stated that "we don't know the answer" when asked if HW3 will be FSD capable.

Musk has said that Tesla owners who have HW3 installed on their cars will receive a free upgrade to HW4, the latest self-driving computer introduced last year.

"HW4 is several times more capable than HW3. Musk said that it's easier to get HW4 to work and it takes more effort to get HW3 to do the same thing.

Tesla has experience in this field, having retrofitted HW2 modules to HW3 for some cars. The problem is that some observers are unsure whether existing Tesla models will be able to be upgraded to HW4.

According to Electrek HW4 is a new computer with a different form-factor. It would not necessarily fit into the same installation location as HW3 in existing Tesla cars.

It seems likely that a customized HW4 version would be required for retrofitting purposes. Musk has described HW3 camera systems as being "capable" with FSD. However, HW4 cameras have five times the resolution. HW4 cameras have also improved their low-light performance. Presumably there's a good reason for these upgrades.

If replacing existing HW3 units with a retrofit HW4 unit sounds like a huge liability, then the idea of removing all eight HW3 camera units and replacing them with upgraded models is also a no-go.

The question remains, however, whether HW4 will be able to perform FSD. Musk is confident that it will. He has been bullish about full self-driving with HW3 for years.

This means that Tesla's self driving is very much like a mid-range Nvidia GPU that is priced sensibly, and that it remains a technology that is tantalizingly on the horizon - visible, almost tangible, and very much imaginable but always just out-of-reach.