Tesla Full Self-Driving: An overview of how it works

We'll also dive into how much this feature costs and why it's part of a new federal investigation.

Brian Cooley Editor at Large
Brian Cooley is CNET's Editor at large and has been with the brand since 1995. He currently focuses on electrification of vehicles but also follows the big trends in smart home, digital healthcare, 5G, the future of food, and augmented & virtual realities. Cooley is a sought after presenter by brands and their agencies when they want to understand how consumers react to new technologies. He has been a regular featured speaker at CES, Cannes Lions, Advertising Week and The PHM HealthFront™. He was born and raised in Silicon Valley when Apple's campus was mostly apricots.
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Brian Cooley
3 min read

If there is one piece of technology that's pretty optimistic, it's Tesla's Full Self-Driving system. There are no self-driving cars on sale today, despite what "FSD" -- as Tesla owners and CEO Elon Musk refer to it as -- promises. We'll dive into what's actually included in FSD, how much it costs and what you want to be aware of when it comes to this system.

While the term "full self-driving" leaves little ambiguity about its aspirations, the technology accomplishes far less than the words imply. As of this writing in August, 2021, FSD is actually a sophisticated version of Level 2 driver assistance, as defined by SAE International, arbiter of many of the world's automotive standards.

SAE levels of driving automation

The levels of driver assistance and autonomy. Level 2 is about as far you can go so far, and that certainly doesn't deserve the moniker "full self-driving."

SAE International

Level 2 driver assistance requires the presence of two or more driver assistance technologies working simultaneously and, critically, as driver supports, not as substitutes for driver attention or operation. In the case of Tesla's FSD, as well as systems like GM's SuperCruise, this means:

  • Speed control via automatic braking and acceleration.
  • Object detection and spacing, whether that's a car being followed or a pedestrian being avoided. 
  • Semi-automatic lane changing where the car executes a lane change when you actuate the turn signal and conditions allow a safe lane change, though GM has just announced that the next version of its SuperCruise will offer fully automatic lane changes without the driver needing to request them via the turn signal. 

Even with all these technologies in concert, the SAE definition of Level 2 reminds us that the driver must remain in full control of the car and oversee its operation at all times. Level 2 replaces some muscle effort more than it replaces much mental effort.

In the gulf between what it's called and what it does, Tesla FSD lies somewhere between a massive overpromise and potentially dangerous innuendo. While many vehicle autonomy technologies have had a high-profile incident or even fatal accident, Tesla's technology has earned more than its share of scrutiny. I normally don't begrudge the auto industry its indulgences in audacious marketing, but when it comes to something as important and risky as vehicle autonomy, I have to draw the line. Tesla's absurd naming of Full Self-Driving to be a detriment to the overall progress of vehicle autonomy: Regulators, insurers and car buyers need to have faith in the tech if its vast benefits are going to scale, and FSD-inspired stupidity won't get us there. 

Two big, square AI processors power Tesla's third-generation full self-driving car computer. Tesla showed the computer at the Hot Chips conference.

Tesla has long indicated that most of its cars have been shipping with all the hardware necessary to achieve what it calls Full Self-Driving, but a recent announcement indicates that a $1,500 hardware upgrade is necessary in many cases.

Stephen Shankland/CNET

If you still want FSD on your Tesla, the path has become more affordable but also more complicated. It used to be you could pay $10,000 to unlock the feature on hardware that Tesla said was being built into every one of its cars. But Tesla recently announced that you could instead pay a subscription fee of $199 a month to unlock FSD. In that case, however, you might have to pay for a $1,500 hardware upgrade, depending on a matrix of your car's model year and original configuration.

Then there's the Level 5 thing: According to the SAE, Level 5 is the only level of driver assist that actually qualifies as fully self-driving. Cars at that level don't even need pedals or a steering wheel. But no automaker is close to offering Level 5 and there's an increasing drumbeat of discussion around the auto industry about whether we'll ever see it in privately owned vehicles. Despite this, in January 2021 Tesla said it could start rolling out Level 5 on some customers' cars by the end of the year. This seems impossible, and Tesla has more recently acknowledged as much to CA regulators. Level 5 on a Tesla is like 5G on an AT&T phone in 2019.

Bottom line: Tesla Full Self-Driving is Level 2 driver assistance, not unlike what some other carmakers offer. You can pay $10,000 or $199 a month to access it in your Tesla, and you might need a $1,500 hardware upgrade to get it.