Gary Zhou 
What I’ve learned using it for 6 weeks and 2000 miles
For the last six weeks I’ve been using Full Self-Driving (Beta) both for local and long-distance driving — virtually all the time. I will often repeatedly push the software to the limit when I know it would be too slow for a regular driver or where it has failed previously. As time goes on, I continually observe new behavior.
In Part 1, I summarized all of the fabulous things that FSD (Beta) does for the driver, as well as what it takes to get it and keep it. Here in Part 2, I relate the shortcomings and failures of the software.
When is FSD (Beta) Too Slow/Timid?
At one-way or two-way stop signs, FSD (Beta) creeps forward so slowly that it’s not useful for normal driving. However, if you signal it to proceed with the accelerator, it will proceed straight ahead or steer the turn correctly, depending on your route. FSD (Beta) stops at the entry to a rotary even when no cars are present. Again, a little pressure on the accelerator solves the problem. Ironically, the behavior at a 4-way stop is generally better and it proceeds more quickly. I think this is because it doesn’t have to look out for cross traffic.
Phantom Braking
You can be driving on perfectly clear roadway and FSD (Beta) will occasionally do regenerative (mild) braking for no apparent reason. Sometimes on the Interstate you will get this mild braking for a large vehicle approaching or a large vehicle or trailer parked near your lane.
I’ve never had hard braking and I keep my foot lightly on the accelerator so that I can compensate for unwanted braking. [Editor’s note: I’ve gotten very hard phantom braking on residential roads.]
Phantom braking is worse with FSD (Beta) than it is with standard smart cruise control. I assume this is because the software is now looking for more things in your lane and it misidentifies some objects. [Editor’s note: My thought was that it was because the Autopilot suite changed from using the car’s radar as well as cameras to only using cameras, but perhaps Fritz is right or partially right.]
When Do I Turn Off FSD?
Notice I said FSD, not FSD (Beta). On limited access roads, FSD will pass slower moving vehicles and make automatic lane changes. FSD will almost always change lanes promptly for a slow-moving vehicle. However, it does not reliably exit the passing lane even when specified in the settings. FSD will also make frequent lane changes on multilane freeways for no scrutable reason. For this reason, I usually turn off Auto Navigation on multilane freeways and make the turns semi-manually. I use the turn signal to initiate the turn because I know that with multiple cameras, it knows better than I do when it is safe to change lanes.
When Do I Turn Off FSD (Beta)?
I turn off FSD (Beta) when making a turn or crossing a road with high traffic where there is no traffic light. Afterwards, I immediately turn FSD (Beta) back on again.
Where Does FSD (Beta) Fail Completely?
Note: These failures are consistent, so I know when to disable the software and drive manually. Some may be caused by errors in the database. However, in item #1, it can see the stop signs — which I know, because they are visualized for me — but it apparently doesn’t use the visual distance information to calculate position accurately.
- At some stop signs, it will stop 10 or 15 feet too early. (This may have improved slightly since V10.5.)
- There is one stop sign turning from 1650 W onto Snow Canyon Parkway in Saint George, Utah, where FSD (Beta) will always run the stop sign. Oh my! Note: this is the only stop sign where I have seen this behavior.
- Right Lane Bias: Exiting from I-15 at 1600 N in Orem, Utah, 1600 N street narrows from two lanes to one lane at a stoplight. FSD (Beta) will consistently not just fail to make the merge but will actively put the car in wrong (righthand) lane. Recently, I saw the same behavior in another location.
- Right Lane Bias: When making a turn or going across an intersection, your car will sometimes turn into a bike lane or other wide lane on the right. It will find the correct land after ~50 ft.
- Right Side Bias: Particularly on a freeway merge when the lane is still double width, your car will cling to the white line on the right. This is unnerving because a normal driver will tend toward the left hand dotted white line where you need to be when the merge is complete. Note: This also occurs with regular Tesla Autosteer.
- Parking Lot Behavior: You can engage FSD (Beta) in the Walmart or UPS parking lot, but good luck having it actually find its way out. In tight quarters, the steering wheel will jiggle and jerk like a Nervous Nellie and it’s as likely to find its way into a blind corner as it is find its way out. [Editor’s note: I have never played with FSD in such circumstances, so this is especially interesting to read.]
Improvements Going from V10.5 to V10.8 to V10.10
One of the great things about Tesla is that you get over-the-air software updates as frequently as once every two weeks. I have seen several significant improvements in the 2 years and 4 months (and over 60,000 miles) that I have owned and driven my Model 3. With FSD (Beta), one hopes that regular updates will fix problems, and we can dream that Elon Musk is correct and that we are on a path sooner rather than later to full Level 5 autonomy that is safer than human drivers and doesn’t need to be monitored.
Reading the release notes for V10.10, it lists 8 areas that have been improved and gives the percentage of improvement to be expected. I must say that I have seen little improvement from V10.5 to V10.10 in the things that I feel are most important. The one significant improvement area is that it no longer brakes for cross traffic that will be gone before you reach the spot.
Can You Report Bad Behavior to Tesla?
There is a small camera ikon at the top of the screen. If you have a situation where the software fails consistently, you can push the ikon and send a short video clip from the cameras to Tesla. I have done this a few times but have seen no change in behavior. In other cases, with traffic, you are so busy intervening you don’t have time to push on the camera ikon.
Comments/Your Experiences
I have listed the things I have observed in the 6 weeks I have been rigorously testing FSD (Beta). Please get back to me in the comments section if your experience has been different, and also if you have seen any behavior that I haven’t observed myself.
