fsd 12.x consistently driving below speed limit!

[bubbyo]

i’ll start by saying i’m still on 12.3 and it’s not fully clear by reading other threads if the more current releases are still exhibiting this problem but i can’t get it to consistently drive at or above the speed limit with “automatic set speed offset” set to either on or off!! very frustrating my question for you is if this is the way tesla intends it to be would anyone purchase fsd?

 

[LoudMusic]

I set mine to 10% and when I engage FSD it displays the appropriate speed. But it usually takes it quite a while to reach that speed if it was well below it to begin with.

The other thing I found strange is, if the speed limit changes while FSD is engaged, it often sets the maximum speed to the speed limit. I then have to manually increase the speed.

It is fascinating that it allows me to just push on the accelerator and increase speed without disengaging FSD or complaining about it. I've only increased slowly and to a reasonable speed, so maybe it gets cranky if you're too aggressive.

 

[JB47394]

It is fascinating that it allows me to just push on the accelerator and increase speed without disengaging FSD or complaining about it. I've only increased slowly and to a reasonable speed, so maybe it gets cranky if you're too aggressive.

As I recall, Dirty Tesla played with this. He found a straight section of road and stomped on the accelerator. FSD was fine with it. No warnings at all. But it's still early days, and that's a bit of an edge case, so we have no idea what Tesla or NHTSA thinks of that sort of behavior.

 

[EVRider-FL]

See this related thread: New FSD v12 automatic speed setting works pretty well

 

[PianoAl]

I find that 12.3.3 is only marginally better. I'd probably still buy FSD, but I wouldn't be happy about it.

There's a huge difference between having the car do all the driving and having to constantly check the speed and adjust it with the accelerator. The adjustment doesn't last, so it's back to monitoring when I could be daydreaming.

 

[RTPEV]

I had a chance to get some good practice with FSD 12.3.3 (or whatever it is) on some rural roads during a trip last week. These were a good test bed because there was little traffic, and there were some good straight sections in addition to curvy sections so I could observe its behavior. Also worth noting is this was in rural New York State where many times when you come out of a town, you just see a speed limit sign that say something like "END SPEED LIMIT 30", at which point you are to assume that the state speed limit of 55 takes over. In other words, FSD has no clue what the speed limit is, and assumes it's still 30.

So first of all, yes, FSD 12 notoriously drives below the speed limit (whether automatic speed is set or not), but usually it will get at least close to the set speed if automatic speed is off). I've had to nudge it with the accelerator sometimes, but if you are patient and the road is straight, it will eventually get there on its own.

But with our without auto speed set, the car basically responds to nudges on the accelerator pedal to indicate you want it to go faster, and it will generally respond and maintain the new speed you've achieved by doing this.

Now I did want to see how the car behaved on those rural roads where it thinks the speed limit is 30. Remember, these are clearly 55 roads (and people generally drive 65 or so on them since they are straight for long sections, with little to no traffic). So I set I was pleasantly surprised to find that FSD did not hesitate to exceed what it thought the speed limit was (based on what its little speed limit sign was showing). It even exceeded the speed limit at times without prompting (very curiously). In fact, at one point it was doing 67 along a road, and I usually like to keep it under 10 over. I wonder if they've been collecting data on how fast vehicles actually drive on those roads and use that as input to the "natural speed" used by the auto speed feature.

 

[derotam]

I have seen this as well. The car does whatever it wants to do with speed, haha. Even with auto speed off, the car regularly drives below the speed limit/speed set point. I will disagree with the statement that it will "eventually" get there on its own. Well either I disagree with that, or that doesn't really appropriately deal with the situation because maybe if I kept going on the current road long enough it would speed up, but the navigation route has me turning in x number of miles and it doesn't speed up by that time so it doesn't matter...

I will assume that this will be fixed by Tesla as it does seem to be a regular occurrence, and nudging the accelerator can *usually help. Sometimes it just slows down again though.

I am on 12.3.3 right now so I don't know about 12.3.4.

 

[ellisol]

20M3LR FSD 12.3.5 Mostly two lane highways
I can confirm the speed issues still exit in this version. The MAX speed setting used to be rock solid with FSD 11.4.9. Since the highway stack is supposed to still be based on 11.4.9, I don't understand the regression. Tesla needs to restore their previous programming and resolve this.