I wanted to decrease speed with cruise control so hit the - symbol several times. The transmission downshifted to3rd.gear. This et approximately 70 mph.
Luckily traffic was stopping. I shut the cruise off & everything seemed fine when I turned it back on.
I didn’t try decreasing speed with the- again.
I averaged 16.3 with the 6.2 w/3$3s which I thought was pretty good
Keith

 

When in cruise control mode, the power-train control computer system will attempt to maintain the set speed, using the power of the engine and/or retardation effect of downshifting the transmission.
If you are going uphill, it may need to downshift to get enough force to get up the hill.
If you are going downhill, it may downshift and de-fuel to use engine braking effect to attempt to maintain the set speed. It may downshift more than once.
This is common in not just Ford trucks, but their cars, also. It's been a power-train strategy for several years now. Even my 2010 2.5L Fusion would downshift going down hill to maintain my set CC speed.

Side note ... This is yet another reason the TFLTruck goobers are just morons. They don't understand how to use the power-train system AS DESIGNED BY THE OEM in their downhill "braking" tests during their IKE challenges. What they do is leave a truck in "Drive" tranny mode, with the T/H mode on, but without CC on, and then step on the brake at 60mph, pulling down to 50mph. But that is only a momentary retardation of speed as interpreted by the power-train control. If they want to SUSTAIN a set speed, they need to engage CC and let the system maintain the speed using throttle AND tranny working in combination. But they never bother to actually read the owner's manuals and understand how the systems are intended to work.

 

It's more apparent when tow/haul mode is on. Do you also have adaptive cruise control? Not sure how that might effect what you are experiencing.

 

I don't disagree with you at all, but I always assumed they were specifically testing how well the exhaust/engine brake worked. The way you describe, it would work better. The only thing with your process is it wouldn't allow the truck to slow down lower than 50, where the way they do it, theoretically it could, if the exhaust/engine brake worked very well.

I enjoy their videos but also realize they have to be taken with a grain of salt. My truck will never see the kind of use that they show, but it is interesting to watch. If someone were to pick which truck they were buying solely off the winner of the Ike Gauntlet Challenge, then I'm sure they've made other poor life decisions. Haha

 

I use cruise as an engine brake rather than wearing out rotors and pads.
I set the cruise at current speed, then slowly lower the set speed with the minus button until I get about 5 miles an hour less that what speed I want to go.
I like the way it works for me and my trailer

on the flip side If I am going up a big hill, I will slow the cruise set speed down 5 mph to prevent the engine from working as hard going up the hill.
for a gas motor I think this works well for me.

 

Well there is no exhaust brake in any gas truck I'm aware of, so while I do agree that would apply to a diesel they might test, it would be a moot point in a gas truck from any brand. And yet the apply the same test to all vehicles.

If you use my method, and want to go slower than 50, all you have to do is tap down the CC; it's just that simple.

Their videos are interesting only in that they are entertainment. They are a ****-poor resource for fair comparisons and lack any credibility from a scientific POV. Your point is valid for sure; they are fun to watch, but anyone who uses their videos as a means a making a purchase decision is going to end up ill-informed.

I wrote them a few years back to offer to explain the physics of how gearing and loads alter their "Ike" challenge results, and they simply said no thanks; they didn't see the relevance. I sent them a file of calculations using manipulated inputs, and they completely ignored it. They are in the business of selling air time for profit, and have no interest of really understanding the physics of how things work. Nothing wrong with making a buck; that's the American way. But they have the option to do it in an informed manner, but they choose not to. So I realized that they value money more than facts, and that their results are always going to be biased by their ignorance.

 

If I am reading you correctly, you hit the - button on the gear stick, correct? If so, this has NOTHING to do with the cruise control, but everything to do with gear selection. Every time you hit the - botton, the transmission will down shift, yet still maintain set cruise speed.
To reduce set speed, go to the left side of the steering wheel where the cruise control buttons are. Now, for every momentary press of the “SET” button, your set speed will reduce by 1 MPH, and for every momentary press of the “RESUME” button, your set speed will increase by 1 MPH.

When you put the gear selector stick in “M”, the +/- button will control which gear you have locked in.....just like a manual transmission.
Hope this helps.

 

I guess we all assumed he was talking about the "Set -" button on the left side of the steering wheel; the actual CC buttons. But you may be onto something if he was stroking the "-" button on the gear-shifter ...

 

Now he/she just has to come back and talk to us!

 

Cruise control absolutely uses brakes to slow the vehicle. You'll likely go through rotors and pads quicker using CC on downhill grades than if you just use manual brakes and/or engine braking (if diesel). If you think CC is going to save rotors and pads, I think you're going to be disappointed.

 

Which is why TFL does not use cruise for the downhill portion. They are comparing the ability of the drivelines alone to maintain vehicle speed, not the braking system. No their tests are not perfect, actually it would be almost impossible for them to be without a massive budget. I like watching their videos, if you look at the meat and potatoes of the tests there is a lot of good information to be gained.

 

Sorry guys, I was away this weekend. No, I used the - on the cruise controls on the steering wheel. I didn't expect a downshift. Nothing seems worse for wear because of it but it was a little tense for a bit.
I didn't dare try it on my way home, I just touched the brake & reset that way.
It was a 1000 mile trip each way & other than that everything went smoothly.
Thanks for the responses although I'm still concerned as to why it happened.

Keith

 

Wait ... What ???
Are you saying CC uses active braking; it engages the brakes to control decent? I find that hard to believe; I think you're wrong. Downshifting the trans to get gear reduction is what the system does, to the best of my understanding and experience. In fact, the entire concept of gear reduction speed retardation is to save the brakes. Not so much to keep them from wearing, but to keep them "fresh" and not overheat them in long, heavy downhill runs. It's a strategy to "save" the brakes from thermal destruction, not make them last an extra 1000 miles in use. And so, it would be completely counter-intuitive to use active braking as part of the CC retardation strategy. It would be creating the very condition it's supposed to avoid.

But - I'm open to learning something new, if you can prove it to me. Do you have a link to a technical article or an official document that describes the this function as you purport it to exist?

 

I think that the adaptive cruise does have the ability to use brakes to slow the vehicle, but the "normal" cruise does not. I don't have adaptive cruise on my truck and it uses a combination of exhaust braking and downshifting to control speed on steep descents. I does it very well, even when towing my heavy fifth-wheel trailer. But it absolutely does not apply the service brakes...

 

The problem with getting technical, is that is mucks up the real world experiences. Winning numbers on paper don't always translate to winning an actual shootout.