Adaptive Cruise Control Behaviour

dtech

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Experienced this several times on uphill mountain driving, when approaching another vehicle that has slowed braking occurs to keep the prescribed distance, but when the vehicle in front speeds up the cruise control seems to apply full throttle and with boost applied the Ranger accelerates rapidly - which then triggers another application of the brakes to maintain the distance between vehicles. Only has occurred on the steeper grades , but scared my wife when she experienced it. Anyone else experience this ? On level road and less steep inclines the ACC works great, but on steeper inclines seems to also allow the speed to fall off a bit more than other vehicles I've owned - but they are 5 and 6 speed trannies which I suspect helps with maintaining consistent speed on steeper inclines.
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slowmachine

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In nearly every vehicle, cruise control works poorly on anything but a minimal slope. When driving the Ranger in rolling hills, it does very good job in Sport Mode, but typically poorly in Drive.

For the best performance in hilly terrain, you need to anticipate, and current cruise technology is only reactive. There is a strong push in the commercial trucking industry to field cruise control systems that use GPS and terrain-mapping to anticipate climbs and descents, and that will probably trickle down to passenger cars, but not any time soon.
 
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dtech

dtech

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the adaptive cruise radar is only capable of sending out a beam so far.

when your vehicle falls off on power (gearing and turbo combined) the gap opens up, but the radar see's empty. so it does what it's programmed and wants to reach your set speed. again depending on the gearing and turbo situation, this can be like a rocket, which many people brag about with their rangers, or anemic because it hasnt shifted gears yet or isnt into boost. then you race into the radar zone again and it picks up the car ahead, and cycles once more...

its the nature of the beast with the programming and drive for that situation. it has it's limitations.
Yeah when boost is available and the tranny has downshifted to a lower gear the acceleration from the cruise control bringing the vehicle back up to the set speed can be like whoa, , but I think Ford might have considered programming the acc to accelerate a bit less aggressively in those situations, wonder if pitch is a consideration to the program.
 

wanted33

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I found that ACC takes a bit of getting used too. The one in my Wrangler reacts differently than the one in my wife's Mustang. I usually turn it off in up hill sections sections to avoid what you just explained. I do like how it react in the down hill sections of the mountains here in N.C. It will hold the speed mainly using the tranny.
 
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dtech

dtech

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I found that ACC takes a bit of getting used too. The one in my Wrangler reacts differently than the one in my wife's Mustang. I usually turn it off in up hill sections sections to avoid what you just explained. I do like how it react in the down hill sections of the mountains here in N.C. It will hold the speed mainly using the tranny.
Ended up turning it off on uphill climbs as when it accelerates so strongly found it unsettling and then feeling the brakes being applied doesn't suit my type of driving.
 


dmeyer302

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Use your foot to keep the speed up during the slow spots. No need to turn the cruise system off, you’re just overriding it momentarily.
 

AzScorpion

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Use your foot to keep the speed up during the slow spots. No need to turn the cruise system off, you’re just overriding it momentarily.
I just used mine for the first time on out trip and this is exactly what I found I had to do. On the first hill it did what @dtech described so from then on I just stepped on the gas the next time so it didn't accelerate so fast.

Mines tuned so the first time it did it I wasn't expecting it and it took of like a rocket. lol It does slow itself back down but now you're on/off so fast you get car sick. :puke:
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