Cruise control - should it work downhill? - Alanovich
Driving my newish (to me) Mazda 6 through town this morning, I flicked on the cruise control at 30mph as it sudddenly dawned on me that it would be a good idea to help me keep to 30 along a road with several speed cameras.

After about 500 metres or so, the road took a dip downhill on what is a fairly steep gradient (bicycles are often travelling faster than cars down this particular stretch). However, the cruise did not hold the car at 30 and it started gathering speed.

I was under the impression that cruise should hold the car at the selected speed whether going up or down hill. Am I wrong? Is this a fault, or is it normal behaviour on a Mazda 6? If I remember correctly, the cruise I had on a Seat Toledo held the selected speed whatever the gradient. And I shall have to try it out now on my wife's Touran next time I'm driving it.
Cruise control - should it work downhill? - Lygonos
Cruise will not apply the brakes unless you have the fancy adaptive type found in top-end Mercs and Honda Legend types.

Thus if you go down a steep enough slope, the car simply "lifts it's foot off the throttle" and gravity takes over.
Cruise control - should it work downhill? - Alanovich
I see. Thanks.
Cruise control - should it work downhill? - Bagpuss
As mentioned above, only the adaptive type cruise controls will apply the brakes, and then only gently. If it's an automatic though, I would have expected the car to change down a gear to prevent the car gathering speed. That's what my old Merc C-Class used to do.
Cruise control - should it work downhill? - Alanovich
It is an automatic, maybe I didn't give it enough chance to change down as I didn't want to start speeding past a nursery and primary school at quarter to nine in the morning! I'll try that out somewhere more appropriate when the need arises.

Overall I'm pretty non-plussed with cruise. On the crowded motorways of the south east I'm forever flicking it on and off and usually get fed up with faffing about with it. And it's not much use in town driving as it's stop-start for the most part. Not a toy I'm overly fussed about having.
Cruise control - should it work downhill? - daveyjp
Chances are it won't drop down - the Touran certainly won't as my A3 doesn't. It tries to keep speed, but you can tell the system is struggling on downhill sections.

I knock cruise off and use a lower gear - putting DSG into S is usually sufficient, in 30 limits this drops it from 4th to 3rd and increases the engine braking.
Cruise control - should it work downhill? - Alanovich
That's the first good use for the "S" mode on a DSG TDi I've heard. It's always seemed pretty redundant to me given that it only holds the car in a particular gear for longer, revving the engine harder, which is hardly the point with a diesel of this ilk I'd have thought.
Cruise control - should it work downhill? - stunorthants26
It depends entirely on the car, some do, some dont. I used to drive a Rover 623 GSi auto which had cruise control and that would change down a gear to give engine braking and maintain the selected speed as did the system on my old Smart ForTwo.

Our Forester however didnt do this at all, nor have many other cars ive driven, so it is model specific.
Cruise control - should it work downhill? - Altea Ego
I have cruise but mine is a manual box so it does not change down. Funnily tho it needs a pretty steep downhill section to make the car run faster than its cruise set.


Cruise control - should it work downhill? - Alanovich
Presuming you're talking about an Altea, then that's probably why I didn't notice this in the near-identical manual Toledo I had.
Cruise control - should it work downhill? - wmo
I have a Mazda 6 with cruise control. Going down a minor slop the cruise control seems to hold the car back a little, but the cruise control will not hold the car back going down a steep slope.

Edited by wmo on 08/04/2009 at 14:58

Cruise control - should it work downhill? - Old Navy
>>On the crowded motorways of the south east I'm
forever flicking it on and off and usually get fed up with faffing about with
it. And it's not much use in town driving as it's stop-start for the most
part.


You have hit the nail, using CC in inapropriate circumstances is a pain and potentially dangerous. I would not have a car without it for the areas I do most of my driving in. Light traffic, motorways and A roads, even our urban areas are a steady 30MPH cruise most of the time. As a rule of thumb we calculate journey times at a mile a minute. My focus 2.0 TDCI gathers speed on a steep downhill when on CC.

Edited by Old Navy on 08/04/2009 at 15:40

Cruise control - should it work downhill? - ForumNeedsModerating
I'm surprised the OP's car doesn't - as it must surely have a fairly sophisticated electronic controller for the change cycle etc., which is probably dynamic to boot.

My CC (with speed limiter) will happily change down & back up to compensate for going down & up hills. It will 'trigger' (to limit the effects of gravity) within about 2kph, i.e. it changes down to achieve engine braking, then change up when the slope flattens.
Likewise, going up hill it will change down if necessary - not that often though since my engine is producing around 390Nm at my cruise speed (60-65mph) which helps to flatten hills quite nicely by itself.

As per Old Navy, my part of the world makes CC a very useful device. There's also some technique to learn about when/where/how to use it - after that it's very intuitive & almost indispensible.

Cruise control - should it work downhill? - Steve Pearce
CC is a godsend in roadworks that have average speed cameras installed.

The longest distance I ever managed to have CC engaged was on a late night trip from Cardiff back to the Newbury area. I engaged the CC just as I was passing the toll booths for the SSC and didn't disengage it until leaving the M4 at J13.

Edited by Steve Pearce on 08/04/2009 at 18:26

Cruise control - should it work downhill? - Falkirk Bairn
If it's an automatic though I would have expected the car to change
down a gear to prevent the car gathering speed. That's what my old Merc C-Class
used to do.


I think the Merc C Class of roughly 2000-2006 had a speed limiter not Cruise Control IIRC

Speeder limiter set to 60mph, car could tootle along at any speed depending accelerator - up to 60mph.

"Normal CC" tries to maintain constant speed except downhill where it is steep.

Newer Adaptive CC on upmarket cars can change autos down and give some engine braking.
Cruise control - should it work downhill? - ForumNeedsModerating
>>I think the Merc C Class of roughly 2000-2006 had a speed limiter not Cruise Control IIRC

Depends on the model of course. Very rare to have speed limiter & not CC. Mine has both.
(can be the other way around though)

>>"Normal CC" tries to maintain constant speed except downhill where it is steep.
>>Newer Adaptive CC on upmarket cars can change autos down and give some engine braking.

Mine has 'normal' CC - not the newer adaptive CC & it changes down a gear (or two) on
steep hills when CC engaged, and then changes up again when on the flat. Adaptive CC (at least on Mercs) will brake for you as well. It will also change down a gear if going up a hill with CC to maintain speed & best gear ratio.

An Audi A6 I had (with CVT gearbox) did the same 'trick' too, i.e. it shortened the effective ratio to provide engine braking to maintain set CC speed. It worked even more sweetly than my C-class does.

It does seem from the posts here that there's CC & there's CC.
Cruise control - should it work downhill? - a900ss
Mine has 'normal' CC - not the newer adaptive CC & it changes down a
gear (or two) on
steep hills when CC engaged and then changes up again when on the flat. Adaptive
CC (at least on Mercs) will brake for you as well. It will also change
down a gear if going up a hill with CC to maintain speed & best
gear ratio.



What year is yours Woodbines? I know you have a 270CDi so I would have thought your car would be better than mine.

I have a '55' 220CDi Auto (Avantgarde SE if it makes any difference). It will change down gears to hold speed on a hill andif it is really steep it WILL apply the breaks to ensure that you don't overspeed. I thought all C Class's did this.

To the previous poster, my Merc has CC and Speed Limiter. I use the CC lots (I'm a heavy motorway user at 40,000 miles pa) but don;t think I have ever used the limiter.

Edited by a900ss on 10/04/2009 at 13:12

Cruise control - should it work downhill? - issieman
I am just about to buy the Mazda 6 with an Activematic drive, would this be similar to the VW DSG system? also is there anything I need to watch out for?
Cruise control - should it work downhill? - Alanovich
issieman, My (2006 55 reg) 6 is an auto with manual option, never heard it called Activematic though. Operates in exactly the same way as the DSG box on my wife's VW Touran, i.e. you can shift the lever to the left when in drive to allow manual changes up and down. The annoying thing is that in the Mazda, you pull the lever back to change up, and push forwards to change down. In the Touran, it's the opposite (forward to change up a gear, backwards to change down). So I have to think about it and have got it wrong in the Mazda a few times.

In the first week of having the Mazda I managed to completely forget I'd switched it to manual once, and revved the bejaysus out of it in first waiting for it to change up when coming off a roundabout. In manual, the car stil changes down to first automatically when you come to a standstill. So watch out for that! Haven't done it again, I had kittens when I realised what was happening, as the rev counter was well in the red.

I've noticed that both boxes don't allow you to manually change up if the car thinks you're doing it too early. You push the gear lever but nothing happens.

Of the two, I find the Mazda's gear box smoother and I find it changes up when I want it to more reliably than the Touran, which has a tendency not to change up to 4th as early as I'd like sometimes. Although that might be an illusion caused by the diesel Touran's engine note compared to the petrol 6.

Edited by Alanovich on 09/04/2009 at 11:50

Cruise control - should it work downhill? - Alby Back
Both my Mondeo diesel and my Signum petrol are manuals. Both have CC. Neither seems to speed up beyond the set speed on the CC when travelling down a steep hill. Maybe it's just that there is sufficient engine braking. I don't know really but I am old enough to think of the whole thing as really clever and almost certainly a form of witchcraft.
Cruise control - should it work downhill? - xtrailman
Some years ago i remember folks raving about CC on the caravan forum i visit.

I assumed that the control aspect meant the car would be kept at the set speed, which should include braking. i will try mine down hill when i think to.

This 2009 xtrail i have has CC, my first car with it, also auto lights, and auto wipers.
All a waste of space, i'll give a little on the wipers, but not the other two.

I only drive in the UK, and on the number of occasions that i have tried to use CC, i've just given it up as a bad job.
My lad says its great in those long 50mph stretches on the motorway. Well i've tried it and every time i've had to cancel it. Set it to 50mph, someone what's to do 45mph, waste of time.
Set to 50mph on the A57 other day, caught up to the traffic queue doing 40mph.

CC is a total waste of time. Sure in america, australia, perhaps france etc, but in the uk not a chance.
Cruise control - should it work downhill? - Old Navy
CC is a total waste of time. Sure in america australia perhaps france etc but
in the uk not a chance.

>>

Sounds like you dont know how or where to use CC, or auto anything.

Edited by Old Navy on 09/04/2009 at 13:13

Cruise control - should it work downhill? - turbo11
I collected new my Mazda5 sport on Saturday. It is the first car I have owned with cruise control. I used to dismiss cc as a waste of time, but I have to eat humble pie. So far I have used it every day. Its great.
Cruise control - should it work downhill? - xtrailman
When i worked, it was as an electrician, technician, technical maintenance engineer, process control technicain, i finnish my final years on PLC, and SCARDA systems.

So i think i am sufficiently technically minded, and i am a avid gadget man, i have remote control lights in my lounge for example, because it is usefull.

On a 2 hour jounrney, down the A1. My speed varied constantly from 80mph down to 30mph, traffic was heavy, as usual, how do you expect to USEFULLY use CC, under these situations.

In the end it was easier to lift and lower my right foot.

Edited by xtrailman on 09/04/2009 at 15:30

Cruise control - should it work downhill? - Old Navy
>>how do you expect to USEFULLY use CC
under these situations.

Simple, you dont. And if you do, you dont know how or when to use it.

Edited by Old Navy on 09/04/2009 at 15:33

Cruise control - should it work downhill? - Alanovich
I think the point being made by xtrailman is that the "when to use it" occasions in this country are pretty much zilch for for many of us. I rarely leave a 40-odd mile radius of Reading these days, and I almost never drive after about 6pm, nor before 8am. On any kind of road around here at those times of day, cruise control is as much use as a one legged man in a backside kicking contest.

If I drove at night on long journeys, I'm sure I'd find it useful in all probability. So, at the moment in my life, I'd really not be bothered if my car didn't have it. I'd swap mine for a nice sunroof in a heartbeat.
Cruise control - should it work downhill? - Old Navy
Exactly, all you have to do is read the post I made yesterday at 14:38. For example I often drive between Glasgow and Carlisle on CC all the way.

Edited by Old Navy on 09/04/2009 at 15:58

Cruise control - should it work downhill? - xtrailman
Well if you meant to say its usfull to use in the middle off the night, why don't you say so?
I'm not a mind reader.

But i do know when something is more trouble than it worth.

I can promote the xtrail satnav voice recognition system, its brilliant, push a button on the steering wheel, shout "destination" and on the next promt shout "home" and the route is sorted.

Not set up the phone side yet, but expect the same sort of thing.
Along with the reversing camera, useful.
Cruise control - should it work downhill? - Old Navy
Well if you meant to say its usfull to use in the middle off the
night why don't you say so?


Because I dont drive long distance at night, do you know the M74 or driving conditions in the almost 400 miles of the UK that exists north of Carlisle?

Cruise control - should it work downhill? - xtrailman
do they have roads up there?
i thought it was just sheep.
Cruise control - should it work downhill? - Alanovich
Ironic all this bickering, as surely an x-trail would be more at home north of Carlisle!

;-)
Cruise control - should it work downhill? - Old Navy
He probably couldnt handle the lack of traffic, and laid back lifestyle. Thats why I dont live in London any more.

Edited by Old Navy on 09/04/2009 at 16:40

Cruise control - should it work downhill? - xtrailman
I live near sheffield. No quite roads here.
Cruise control - should it work downhill? - Old Navy
Mr Xtrail,

As you live about 200 miles from the south coast and about 500 from the wet bit at the top, I would reccomend exploring the big bit to the north, miles of beautiful beaches on the west coast, mountains from Perth up, distileries welcome visitors with free tasters, the possibilities are endless. I live here by choice, not because I was born here or have to. Cruise control works here too, (motoring link).

You are not Mr X are you?

Edited by Old Navy on 09/04/2009 at 16:56

Cruise control - should it work downhill? - xtrailman
No not "X", was "cess", when i was at work, must admit fort william is the furthest north i've been.

I tow a caravan, and enjoy fishing, so apart from the scenery i don't find much to draw me up past newcastle, were my lad lives.

Had a couple of pleasent hols around Ulswater in the lakes, but it seems to rain a lot.
To be honest the peak district, a few miles away takes some beating, but its a traffic nightmare.
Cruise control - should it work downhill? - barney100
My 2000 Merc CLK holds the speed on cruise and also has a limiter which holds you at any set speed you select, very useful in my quest not to give Mr Brown any easy money.
Cruise control - should it work downhill? - gordonbennet
I use CC in the truck if i'm on a 50 mph easy day, it works well as i'm probably the slowest vehicle out there, but always having to brake on any downhills section as the weight just carries the thing away.

Have CC on our pick up which is incidentally one of the highest geared vehicles i've owned (80mph at less than 2200rpm) , and as such and being proper auto has virtually no engine braking...maybe this is a common theme with CC'd vehicles that overspeed easily downhill?
I don't think I or Sheeee has used CC for months, by the time you've found a road to use it on, you've caught up with someone who can't keep up a constant speed over 40mph to save their lives (why is this so bad these days), and should you overtake them dual or single road they will without fail accelerate on you and then slow down again.

But then being a poor driver i don't know how to use it properly anyway..;)
Cruise control - should it work downhill? - Old Navy
But then being a poor driver i don't know how to use it properly anyway..;)


You may be poor GB, but only the drivers "trained" to car standard will consider you unskilled.