This morning, I set my CC to 58 (speed limit 55). After several miles of standard traffic, I disengage by lifting the stalk up one click and continue driving as normal. Not sure why, but I re-engaged at around 45 mph by clicking down one click (instead of two to restart), and the car speed up to 58 and resumed. I repeated this multiple times. It made sense, as the speed CC was previously set at stayed in the circle below your actual speed (where I think it previously just mimicked your real speed). Now, your resume CC speed remains static in the small circle and clicking down on the stalk one indent (after having set the CC speed previously), resumes just like any other car.
This is not new. The problem is that the rules the system goes by are complex, non-intuitive, and confusing. Here's a summary of how TACC behaves on the Model 3:
1. If you have not previously set any speed AND the car has not identified the speed limit of the road you're traveling on, then engaging TACC will set the car to your current speed.
2. If you have previously set a speed AND the car has not identified the speed limit of the road you're traveling on, then two different things can happen:
A. If the car's current speed is less than the previously set speed, then engaging TACC sets the car to the previously set speed (this is classic resume).
B. If the car's current speed is greater than the previously set speed, then engaging TACC sets the car to the current speed.
3. If you have not previously set any speed AND the car has identified the speed limit of the road you're traveling on, then two different things can happen:
A. If the car's current speed is less than the identified speed limit + the user-set speed limit offset, then engaging TACC sets the car to speed limit + user-set speed limit offset.
B. If the car's current speed is greater than the identified speed limit + the user-set speed limit offset, then engaging TACC sets the car to the current speed.
4. If you have previously set a speed AND the car has identified the speed limit of the road you're traveling on, then three different things can happen:
A. If the car's current speed is less than the previously set speed AND the previously set speed is greater than the identified speed limit + uset-set speed limit offset, then engaging TACC sets the car to the previously set speed (this functions identically to classic resume, and this is what happened in your case above).
B. If the car's current speed is greater than the previously set speed AND the previously set speed is greater than the identified speed limit + uset-set speed limit offset, then engaging TACC sets the car to the current speed.
C. If the previously set speed is less than the identified speed limit + user-set speed limit offset, then the car does not remember the previously set speed. TACC behaves as in #3 above.
Furthermore, if you are in situation #3B, #4A, or #4B, you can override the normal TACC behavior and immediately set the car to speed limit + user-set speed limit offset by engaging TACC with a full press down and hold on the gear stalk.
Your situation that I quoted above was situation #4A, and I can also infer that your user-set speed limit offset is probably set to 0 MPH.
But as you can see, there are 6 different factors that go into how TACC behaves:
1. Whether there is a previously-set speed or not.
2. Whether the car has identified the speed limit or not.
3. The car's current speed.
4. The car's previously set speed.
5. The current speed limit.
6. The user-set speed limit offset.
Changing any one of those things changes how TACC behaves, and in my opinion, the programming here is far too complex. No driver can reliably predict what TACC is going to do in any situation. The one saving grace is that the speed at which TACC will set the car to is displayed in gray in the circle, so you at least know what speed is going to get set when you push the stalk. But in many (most?) situations, that may not be the speed you expect or want.
