2018 Adaptive Cruise question.

[HoosierDaddy]

I have a 2013 Cadillac with manual trans that lets you shift without disengaging cruise. Cruise is just suspended during the shift.

From test drives before ordering, I knew my 2016 Mustang with ACC would not have that feature. When the 2017s arrived, they were the same.

Since the Mustang has all the sensors the Cadillac needs to accomplish this, I would like to know if the 2018 Mustang is the same.

I asked this in another thread which was on topic but the responses took that thread way into left field, so I'm asking here.

It should be obvious that its not desirable for a driver to be forced to find and press a resume button every time the trans gear changes. If it was desirable, you would have to do that every time your auto trans changed gears. And with adaptive cruise, its going to be common to down shift as traffic backs up. Maybe its different elsewhere, but the freeways here slow to where the gear you were in for 65 MPH is a bit too high for 20 MPH. The whole point of adaptive cruise is to not have to constantly manually use the gas and brake, not to substitute that for constantly resuming the cruise. LoL

There are no legal or technical road blocks, or my 5 year old Cadillac with manual trans wouldn't let you shift without disengaging cruise. It's not hard for a car to know if the clutch is engaged and the car is in SOME gear just based on a sustained ratio of engine to wheel RPMs.

SO.... do the 2018s with manual trans and ACC let you shift without making you resume cruise after every shift?

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[HeavyMetalMonk]

No

 

[HoosierDaddy]

No

Thanks.

 

[HeavyMetalMonk]

No problem!

 

[TexasRebel]

The more I think about it, the more liability Cadillac has exposed themselves to...

What are the limitations? What happens if you disengage the clutch at 70mph, traffic slows to 10 mph and you shift to 2... forget CC was enabled and set... and engage the clutch? Does it try to hit 70 in 2nd? Does it recognize a 60 mph difference and cancel itself?

 

[HeavyMetalMonk]

The more I think about it, the more liability Cadillac has exposed themselves to...

What are the limitations? What happens if you disengage the clutch at 70mph, traffic slows to 10 mph and you shift to 2... forget CC was enabled and set... and engage the clutch? Does it try to hit 70 in 2nd? Does it recognize a 60 mph difference and cancel itself?

Well, it'll hit the rev limiter worst case I suppose.

 

[HoosierDaddy]

What are the limitations? What happens if you disengage the clutch at 70mph, traffic slows to 10 mph and you shift to 2... forget CC was enabled and set... and engage the clutch? Does it try to hit 70 in 2nd? Does it recognize a 60 mph difference and cancel itself?

The point of adaptive cruise (as opposed to regular cruise) is to automatically slow down (including heavy brake usage) or speed up as traffic in front changes speed.

So, in your scenario, it would not try to accelerate to 70 because there is a car in front of you going 20 MPH (changed from your 10 because cruise has a minimum speed). When that car speeds up or the lane clears, yes the car would try to accelerate to 70 in 2nd with the amount of throttle its programmed for; you will always need to shift, exactly as you would without cruise being set. Adaptive cruise eliminates the need to brake or accelerate for traffic. It doesn't eliminate the need to change transmission gears, manual or automatic.

If I am driving with cruise set to 70 and traffic slows down, ACC will get off the gas and apply brakes as needed to match speed. When speed drops enough to need a downshift, I shift and immediately hit resume. When traffic allows, ACC accelerates the car towards 70; when an up-shift is needed, I shift and immediately hit resume. So hitting resume is a given after every shift up or down. So it should be automatic. Maybe an option to NOT do it automatic for people with bad memories. ;)

Now if you are saying that a driver would forget they had set cruise and still not remember it when the car suddenly started accelerating and simultaneously forget that brakes are used to slow a car down (which also disengages cruise), then I guess such a person could find themselves driving across country bouncing off the red-line if cruise was allowed those RPMs.

If you've ever spent any time driving an adaptive cruise manual trans car in traffic (and adaptive has no point whatsoever without traffic), you would quickly realize, you aren't about to die.

 

[TexasRebel]

I'm not so sure.

I've used my accelerator to pass people while cruise was set... (I'm of the "get around as quickly as your equipment will allow you camp)
after the pass, you get back in the lane and let off the throttle to engine brake back down to speed... and if you forget cruise was set it's a pretty unsettling feeling when the engine braking just quits. Never mind if additional acceleration was to be involved.

Of all of the junk taught in driver's education, "don't use cruise control in traffic" was probably the soundest piece of advice. Right after "even if it's not your fault, it's still going to hurt/cost."

 

[HeavyMetalMonk]

I'm not so sure.

I've used my accelerator to pass people while cruise was set... (I'm of the "get around as quickly as your equipment will allow you camp)
after the pass, you get back in the lane and let off the throttle to engine brake back down to speed... and if you forget cruise was set it's a pretty unsettling feeling when the engine braking just quits. Never mind if additional acceleration was to be involved.

Of all of the junk taught in driver's education, "don't use cruise control in traffic" was probably the soundest piece of advice. Right after "even if it's not your fault, it's still going to hurt/cost."

I still don't see how this could be a problem. If you forget (can you forget that fast?) it's going to go back to your set speed, or whatever speed the car in front of you is going.

 

[DukeGaGa]

I'm pretty sure there's a speed and gear limit for cruise control, i.e. you have to be above that speed and gear to be able to use the cruise control, I might be wrong, looking through the owner's manual right now to make sure. And I'm talking about manual for the gear thing of course.

Edit: can't find anything related to gears, but you might want to try to turn on cruise control in 2nd or 3rd gear and see if it allows, the manual did say 20mph is the lower speed limit. http://www.fordservicecontent.com/F...etCode=US&languageCode=EN&VIN=&userMarket=USA

 

[Norm Peterson]

... the freeways here slow to where the gear you were in for 65 MPH is a bit too high for 20 MPH. The whole point of adaptive cruise is to not have to constantly manually use the gas and brake, not to substitute that for constantly resuming the cruise.

This happens constantly?

I rather doubt that CC - active or otherwise - was ever intended to be used in traffic where the speed is likely to frequently change by that much.


Separately, how far are you willing to let your own ability to maintain appropriate speeds and following distances decay? Why?


Norm

 

[HoosierDaddy]

I'm not so sure.

I've used my accelerator to pass people while cruise was set... (I'm of the "get around as quickly as your equipment will allow you camp)
after the pass, you get back in the lane and let off the throttle to engine brake back down to speed... and if you forget cruise was set it's a pretty unsettling feeling when the engine braking just quits. Never mind if additional acceleration was to be involved.

Its human nature to feel unsettled until you are familiar with something or forget that you did something.

Of all of the junk taught in driver's education, "don't use cruise control in traffic" was probably the soundest piece of advice. Right after "even if it's not your fault, it's still going to hurt/cost."

Well, yeah, I wouldn't use DUMB cruise in traffic which is what they were talking about. It was recommended because dumb cruise could plow right into someone, if you were distracted (remember that point).

Adaptive cruise is safer than NO cruise in traffic because EVERYONE is distracted a few times in their life by a strange sound, a car veering toward them from another lane, their kid in the back seat throwing up, nude hitch-hikers, etc, etc. If that happened without ACC, and the car in front of you slowed down suddenly at that exact moment, you might run into them. With adaptive cruise, you won't because it will match their speed while you are occupied trying not to teach your kid swear words.

The entire purpose of Adaptive Cruise is to be used in traffic. ACC doesn't do anything different than dumb cruise if there isn't anyone in front of you going slower. If people were always worse off with adaptive cruise, it wouldn't be legal or nobody would buy it.

Now people can debate whether adaptive cruise or automatic transmissions or seat belts or turn signals make the world a better place. But its moot when they already exist.

 

[HoosierDaddy]

I rather doubt that CC - active or otherwise - was ever intended to be used in traffic where the speed is likely to frequently change by that much.

Well if it was never intended for that, it would be engineered to disengage in automatic transmission cars in that situation. It doesn't because it IS intended for that.

Separately, how far are you willing to let your own ability to maintain appropriate speeds and following distances decay?

I won't argue that your skills would not decay because I don't know you that well. You shouldn't assume mine will for the same reasons.

But I'll will submit to a polygraph or practical tests (at your expense) to confirm I can still read a speedometer (maintain a speed) and recognize a proper following distance. Those abilities have nothing to do with what your feet are doing. Now if you are implying that someone would lose the ability to manipulate the throttle to keep the speedometer in one place, if you can produce one such person, I will concede that THEY should not use adaptive cruise! No, on second thought I will concede that they should ONLY drive with adaptive cruise. ;)

I get the fear of the unknown some people have. I have them too until first hand experience banishes them. There was a time many people believed a person would simply die if they ever exceeded 100 MPH.

 

[goldengooner]

Very interesting discussion
I love my ACC, but in heavy traffic its pretty pointless, as i think under 20mph it disengages anyway.
I use it a lot on the motorways (highways) and as someone said, will pull out shoot past a few cars, then pull back in and let it take over and slow the car down.
What my passengers find scary and also Steph, is when a car cuts in on you, and you wait for the car to decide when to brake, have to admit do have my foot hovering above the brake.
Also when you start to pull out, and feel the car wanting to leap, without you doing anything, that scares the dodo out of her
Also find its better for the petrol

 

[HoosierDaddy]

What my passengers find scary and also Steph, is when a car cuts in on you, and you wait for the car to decide when to brake, have to admit do have my foot hovering above the brake.

When someone cuts in front at a much slower speed, it would be bad to NOT have your foot over the brake. Never trust anything with your life if you don't have to. So that seems normal. And nothing wrong with braking yourself if ACC waits longer than you would.

And one thing I would like to see improved in the braking department relates to that.

I sometimes brake earlier than ACC would, not because it might hit the car in front but because it doesn't know about the tailgater behind me who is more likely to hit me if ACC brakes later and harder.

Until ACC knows what's happening behind you, it should have a setting for maximum braking target. And without a setting, a lower fixed target than it uses now. Obviously brake harder than that if someone slower cuts in front and the target braking Gs wouldn't be enough. But as you pointed out, Ford's ACC currently will not apply the brakes when someone cuts in front until later than it could.

There is no doubt it is aware of the speed difference, it just waits longer than is preferable when someone is tailgating or when someone wants to minimize braking for passenger comfort.

ACC will apply brakes hard enough that an unbelted passenger would have to brace themselves with their hands to stay in their seats. I'm just using that to convey how hard it will brake to anyone who hasn't experienced it, not suggesting anyone would allow a passenger to be unbelted.

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