[Sterling]

Having just completed a 1300 mile roundtrip I had ample opportunities to use the Smart or Intelligent Cruise Control on a Palisade Limited. Two things I noted: the first is when you set a following distance and you close the distance the cruise control automatically reduces your speed, this I understood would happen. My question is how is the speed reduced. My experience over this trip has led me to believe the Palisade automatically applies the brakes??? and transmission to slow the vehicle down. If the brakes are applied do the brakes lights come on as well. My experience was during daylight so I could not see the brake light illuminate.

I also noticed that when you are going down a hill, the Palisade will maintain the set speed EXACTLY. Unlike other vehicles I have driven the Palisade holds the speed constant. It does not allow for the 5 to10 or so mph increase that going down a hill will cause. When I was going down a hill if I lowered the speed of the cruise control setting the Palisade would automatically lower my current speed to match. I went from 70 to 55 going down an incline without my choosing to apply the brakes or manually selecting the next lower gear.

 

[wingflywx]

I am not sure about going down hill. But I had experience with the smart cruise following. It depends on how fast the car in front of your reduces its speed. In most cases, I feel the cruise control just let go some of the gas pedal so the car slowly slow down. Similar things is if a car cuts into your lane but as long as it is going fast enough, your car do not brake immediately to achieve the following distance you set. However if the car in front of you reduces its speed significantly, you can feel your car apply the brake. Sometimes it is overdoing comparing to a human driver. For example, in one lane road, when the car in front of you slows down significantly before turning right on a cross road, you can feel smart cruise is pressing the brake quite a lot and long away from the car. Human driver probably will simply let go the gas pedal and slide, the car in front of you can finish the turn before you reach the cross road.

 

[Sterling]

That is precisely what I have experienced.

 

[CPRider]

I believe the cruise control is using a combination of engine braking and brakes to regulate speed going downhill. I base this on having watched the tachometer during descents. I've seen the RPMs increase multiple times while going downhill with the cruise control on. I'm pretty sure that's because the car was designed to spare the brakes by using the engine to slow.

An interesting experiment would be to manually downshift until you're going at the target speed without cruise control on during a steady descent, then compare that RPM to what you see with cruise control on at the same speed.

 

[tallLeRoy]

Yes the brake lights do come on when the smart cruise control slows with the brakes.