Why does my M3 do this (re: braking)?

[MikeRTX]

There is one highway off-ramp where my car will automatically brake and change the AP max speed setting progressively as the posted speed diminishes. Just this one. Nowhere else does it do this.

What happens: I'll have (standard, not enhanced or FSD) AP set to 70, and while leaving it enabled I'll start off this long off-ramp. The speed limit on the ramp then goes to 55 and the max "set" display changes to 55 automatically and the car slows to 55. Then the speed limit decreases to 35, the displayed max speed changes to 35, and the car slows further.

I've played with this on other off-ramps and other places where the posted speed changes, and nowhere else does it automatically change my max speed setting as the speed limit changes. The only thing different about this particular off-ramp is that there's a SC station at the intersection of the off-ramp/service road and the cross street. Is the car automatically slowing down for the SC?

Anyone else notice AP automatically altering your set speed for speed limit changes?

 

[nicksp]

Mine doesn't change speeds as per street speed limits. If I engage TACC and the street speed limit goes down from 55 to 45, my speed still stays at 55.
What settings do you have where your car does that?

 

[bookiepilot69]

There is one highway off-ramp where my car will automatically brake and change the AP max speed setting progressively as the posted speed diminishes. Just this one. Nowhere else does it do this.

What happens: I'll have (standard, not enhanced or FSD) AP set to 70, and while leaving it enabled I'll start off this long off-ramp. The speed limit on the ramp then goes to 55 and the max "set" display changes to 55 automatically and the car slows to 55. Then the speed limit decreases to 35, the displayed max speed changes to 35, and the car slows further.

I've played with this on other off-ramps and other places where the posted speed changes, and nowhere else does it automatically change my max speed setting as the speed limit changes. The only thing different about this particular off-ramp is that there's a SC station at the intersection of the off-ramp/service road and the cross street. Is the car automatically slowing down for the SC?

Anyone else notice AP automatically altering your set speed for speed limit changes?

Hi Mike. I have had pretty much the same situation with all of my Teslas. (I have had eight so far.) Accordingly, I thought it was normal. To be honest, though, I haven't paid close attention to it as far as specific off ramps are concerned. I will keep a better eye on it and see if I can see any variations. I think I have a related question though. We have roundabouts in our area and I have noticed, on a couple of specific roundabouts, that as I approach, my car just slows down for no reason well before the roundabout. I have to keep an eye on my rearview mirror to make sure somebody doesn't run up on my butt when this happens. Anyone else experiencing this?

 

[MikeRTX]

Hi Mike. I have had pretty much the same situation with all of my Teslas. (I have had eight so far.) Accordingly, I thought it was normal. To be honest, though, I haven't paid close attention to it as far as specific off ramps are concerned. I will keep a better eye on it and see if I can see any variations. I think I have a related question though. We have roundabouts in our area and I have noticed, on a couple of specific roundabouts, that as I approach, my car just slows down for no reason well before the roundabout. I have to keep an eye on my rearview mirror to make sure somebody doesn't run up on my butt when this happens. Anyone else experiencing this?

Yes! I also have this happen. At first I thought the car was reading the yellow diamond warning sign and reacting to that. But at other roundies it doesn't brake (?)