Cruise control slightly jerky between 60-70 MPH

[dbsb3233]

I use ACC 98% of the time on the highway. Above 70 MPH it's nice and smooth. But between 60-70 it's slightly but consistently jerky. Not enough to actually change the speed a full 1 MPH, but I can feel the car fighting itself to keep a constant speed. And I can see the power meter vacillating back and forth every half second or so. I can feel the little surge then pullback, back and forth.

It's fairly subtle, but it's consistently there. It's just enough to feel it and annoy me a little. Anyone else feel the same thing?

 

[bicycleguy]

Yes I feel it and it is annoying in that the engineer in me recognizes it as a poorly tuned control system. The reason it may not happen above 70 is that aerodynamic loads keep the system out of the regen region. At slower speeds the car can drift into regen mode and for whatever reason it seems to be a big first step. It slows to much and then accelerates to much to catch up. They need to study more about how to transition between linear(normal control) and non linear(turning regen on and off) control.
This is also why I can get better efficiency without ACC, something I've never been able to do on any other car, even with after market or home made cruise control.

 

[dbsb3233]

That's the way it feels to me too, that it's applying regen to keep jerking you back a little. The regen is SO strong on this car that even applying a short blip of it makes you really feel it.

It's similar to the annoyance of trying to match speed when dropping out of ACC. If you don't get the pedal pressed exactly to the same speed, you get a harsh jerk from regen slowing you too much too fast. It's like there's zero transition blending on this car. It could really use some better transition tuning.

Until they get that done (if ever), I'd like an option for lighter regen. Both STANDARD and HIGH seem very strong (like 8 and 9 on a 1-10 scale). We could use a 5, which would still be plenty strong enough for normal slowing, but hopefully make those transitions less harsh.