cruse control quirks

If +/- 2 MPH gets you too close to other cars........you were too close to them in the first place.
Seriously.

Does your model have an ECO button?
Maybe it would maintain the speed better with ECO off ??
I haven't tried my C to see.

 

Are you in ECO mode? If so, turn that off and go back to Normal, which has tighter speed control.

 

i've never had any luck with any of our hybrids holding a constant speed on hilly terrain.

 

Well then we are back to this:

 

First world problems.

 

Plus or Minus 1 or at most 2 mph on hilly terrain?

And this is a problem....why?

Cruise Control isn't magic, it still is just a machine working against the forces of gravity and momentum. Cruise control cannot see or pre-compensate for changing inclines, why would you expect it to be able to keep the perfectly constant given those parameters.

I've never owned a vehicle with cruise control that COULD keep the speed perfectly constant all the time especially up and down hilly terrains.

My advice would be when going up and down hilly terrain? Just look at the road ahead....keep your eyes off the speedometer. You'll never even notice that you momentarily lost or gained a single MPH or two.

I

 

sometimes i wonder if the cruise is working on the guy i'm catching up to.

 

I think that point is that he wouldn't notice, if not for the cars near him that are also using CC.

 

Again what are your expectations?
Up and Down Hills or perfectly flat terrain, I don't expect cruise control to be a complete "Auto Pilot".

You can set CC on an "Autobahn" stretch of highway, and still come up on other vehicles that are going slower, faster and may or may not be using cruise control themselves.

Bottom line, I don't think 1-2 mph fluctuations in speed, especially while going up and down hills, is a problem at all.

 

Every car with CC I've had works pretty much the same way. The Prius might be a little less sensitive to gradual inclines than some heavier cars, but your description seems reasonable. The Prius does seem to do the +1/+2 nearer the top of a hill more than I remember with our old van, but nothing problematic.

 

Over five different models on four different brands, I've seen a fairly noticeable difference among CC systems. The Prius in ECO (I don't use the other modes) has a wider variance than average, but I don't think think it is as wide as my long gone '84 Ford 2.3L.

 

My CC works as well as I've seen CC work on any vehicle.

 

I adhere to the majority of comments, my CC works basically the same; +1MPH is a normal gauge but, I do not have hill conditions to test; we are flatlanders around here.

 

If it's a problem, upgrade to the Five with DRCC. The speed will still vary a little bit, but you'll never get too close to anybody else because of it.

 

If anything, the Prius CC is supreior.

Normal CC units will aggressively add gas when the speed drops 2 mph below the set speed (going up hills). The Prius does the same.

Normal CC units simply coast when going downhill, regardless of speed gain. The Prius will engage regenerative braking to resist excess coasting. Until your battery maxes out, you have the car trying to slow you down to the set speed without using the brakes. To my knowledge, modern CC units don't do this on other cars.

 

The Prius has a significant edge with regenerative braking, but there are other cars (including my Honda...) that use a combination of engine braking and transmission downshifts (using the transmission's grade logic) to maintain the set speed on downgrades.

 

Sure they do. It is called compression braking.
It is not as pronounced as the regen action but just about as effective.