Does Cruise Control give better or worst MPG

[kevenh]

<snip> ie coasting in neutral for as long as practical <snip>

That will use more fuel, if you leave it in gear downhill with the engine on overrun the fuel supply is cut off, in neutral the engine is still consuming fuel.

What Lenny ses; cars with ECU will have fuel cut off sensors and scenarios like driving downhill or when drivers lift off the accelerator as they approach a queue, etc. will cut fuel supply.

Hypermillers use that feature to extract extra mpg
edit: that link I found to hypermilling isn't the best but if you're intrigued is a start place...
edit2: switched out the dormant/dead site for an active one...

 

[BusyBuilder]

I have found CC good up here on main roads. But when we travel down to Hereford via M74 which is good for using CC, then onto M6 which we find rubbish for CC we generally don't use it much on M6.

 

[robnchris]

robnchris Think you did.???

One weak scenario of the Adaptive CC is eg. approaching a Round a Bout on a dual carriageway, you have the CC speed set at 70mph the car in front slows down, your car also slows down, then he pulls into the outside lane to turn right at the R-A-B, your car see's a clear road ahead and will take your speed back up to 70mph, so it's not a set it and leave it, you have to be pro active which isn't difficult as the controls are at your finger tips.

Don't cherry pick the little bits, tell the whole story.

 

[kevenh]

Most of my last cars for 2 decades had cruise control.
I used it all the time.
Just don't expect to read a book when it's engaged.
Look around - but forward especially. When cars ahead are slowing down, knock off the cruise.
When the traffic speeds up hit Res / Resume or your equivalent button.

Your mpg will be decent with CC if you're looking ahead and anticipating when to knock off cruise, & then you also benefit from hypermilling too - you don't think my last post introduced that word for nought do you?

edit: oops. some words missing so sense make did not - oh! that's just words in wrong.
NVM

 

[Skez]

ie coasting in neutral for as long as practical

As previously said, this is actually detrimental to fuel consumption, more seriously it means you aren't in proper control of the vehicle.

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[Dorset Diver]

If I'm driving the MPG using CC is better. If Dorset Lady is driving the MPG is better without CC. So very very annoying .

 

[ctc]

Spent years sitting behind drivers who can't maintain a fixed speed. I've never understood why not but it seems to similar to drivers who leave their rear fog light on, signal left and turn right. CC should be compulsory and under my control.

 

[poppycamper]

Sorry robnchris But your grasp of the English language obviously differs to mine.
My understanding is that E.G. means for example so you are therefore saying "Take the example of approaching a roundabout under cruise control at 70mph etc etc." Which is irresponsible!!

 

[robnchris]

Sorry robnchris But your grasp of the English language obviously differs to mine.
My understanding is that E.G. means for example so you are therefore saying "Take the example of approaching a roundabout under cruise control at 70mph etc etc." Which is irresponsible!!

It's not about a grasp of English language, it's about reading and interpreting what is written, E.G. being an example of what CAN happen...
The example is as explained, you have your CC SET to 70mph. Not that you are travelling at 70mph.(other speeds are available) obviously being an Adaptive CC system your vehicle will only be travelling as fast as the vehicle in front of you.
So approaching the R-A-B he slows down which means you slow down, I made the silly mistake that people reading this would naturally assume everyone slows down for a R-A-B.
The danger comes when the vehicle in front unexpectedly moves into the outside lane to turn right, your vehicle now sees a clear road ahead and accelerates.

If that is confusing then I apologise

 

[kevenh]

It's not about a grasp of English language, it's about reading and interpreting what is written, E.G. being an example of what CAN happen...
The example is as explained, you have your CC SET to 70mph. Not that you are travelling at 70mph.(other speeds are available) obviously being an Adaptive CC system your vehicle will only be travelling as fast as the vehicle in front of you.
So approaching the R-A-B he slows down which means you slow down, I made the silly mistake that people reading this would naturally assume everyone slows down for a R-A-B.
The danger comes when the vehicle in front unexpectedly moves into the outside lane to turn right, your vehicle now sees a clear road ahead and accelerates.

If that is confusing then I apologise

Maybe poppycamper meant that by the point people are changing lanes to confuse your adaptive CC you left it too late to disengage it.

But I've never driven with an adaptive CC system. Do they get you safely a round a roundabout engaged?

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[poppycamper]

The example is as explained, you have your CC SET to 70mph. Not that you are travelling at 70mph.(other speeds are available) obviously being an Adaptive CC system your vehicle will only be travelling as fast as the vehicle in front of you.
Circa 4t moho following a mini and he breaks hard. Gosh..

Ok robnchris . I accept you are not travelling at 70mph even tho you have that set on cruise.
I certainly would not be happy having the car in front of me dictating my speed.

I made the silly mistake that people reading this would naturally assume everyone slows down for a R-A-B.

However this quote confuses me even more.
Does cruise detect a vehicle already on roundabout coming from the right...don't think so... so yes if clear no need to slow down(assuming you ain't going at 70mph) however if there is a vehicle on roundabout then YES I would assume everyone would slow down!!
Again your comments need explanation???

 

[poppycamper]

But I've never driven with an adaptive CC system. Do they get you safely a round a roundabout engaged?

kevenh i have had cruise for many years but never adaptive
I have however been a passenger with one and IMV the disturbing part of it was I.E. (oops sorry) when on a dual road and approaching a slower moving vehicle if you did not pull over to next lane soon enough it would brake just as you were pulling into next lane..... not good if you had judged it to get in front of vehicle coming up behind without cutting him up.
Why are cars becoming less dependant on drivers ability.....Because drivers don't need that ability any more...the cars do it for them.
No wonder etiquette on the roads these days is appalling!!

PS That car also had auto parallel parking... but he did not have the b@@ls to use it

 

[Tiny]

Adaptive cc does not seem to have good press on here, so what do you think of driverless cars! Would you want to be a passenger?

 

[poppycamper]

Adaptive cc does not seem to have good press on here, so what do you think of driverless cars! Would you want to be a passenger?

Only if I was in driving seat..

 

[dunnah01]

Adaptive cc does not seem to have good press on here, so what do you think of driverless cars! Would you want to be a passenger?

No - I like driving

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[Ivory55]

If you go for an assessment at one of the large haulage firms , they expect to see you get up to speed and on to cruise control, but as already said 6 to 8 mpg makes a lot of difference on a hgv. Unless it’s a tipper then it’s flat out to get the bonus.

 

[poppycamper]

If you go for an assessment at one of the large haulage firms , they expect to see you get up to speed and on to cruise control, but as already said 6 to 8 mpg makes a lot of difference on a hgv. Unless it’s a tipper then it’s flat out to get the bonus.

Ivory55 Do lorry's have adaptive Cruise or just normal once speed set by driver it stays at that speed until disconnected by driver???

 

[Ivory55]

Ivory55 Do lorry's have adaptive Cruise or just normal once speed set by driver it stays at that speed until disconnected by driver???

I normally only drive old motors, but I have had a go in a new daf that slows down for you as it reaches the top of a hill or if a car cuts in front of you. Not sure I liked it, but then not used to stuff like that.

 

[Ivory55]

Ps even motors with gear sticks. Haha

 

[gus-lopez]

They have very limited use in most of the rest of Europe

News to me? I use it 95% of the time every day travelling locally even down my road with a 60km limit in 4th gear.

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[poppycamper]

Anyway back to OP's question.
Does cc improve mpg... depends how you use it.
I use it all the time but switch it in and out as road dictates
Knock out on approach to round abouts and corners to slow down without using brakes.
Off going up hills n use good old foot...
Motorways to follow traffic (I don't tend to lane hop) increasing/decreasing speed manually on cruise.
You get the picture... is it more fuel effienct.. dont know but it makes for a more relaxing drive.

 

[Madcaravanner]

Use it regularly in the car, even in 30 and 40 limits.
i much prefer on an auto, and independent test show as it keeps constant speed better than we do, it is marginally more economical.

So do I but that's for a simple reason my back pain is more comfortable when relaxed,
I am not too worried about the amount of fuel I save but as on long trips it is a saving as unlike some others our cruise doesn't floor it on hills and over a certain level it switches off - and the one in the car is tied in to the ECO control so never accelerates fast anyway

 

[robnchris]

Ok robnchris . I accept you are not travelling at 70mph even tho you have that set on cruise.
I certainly would not be happy having the car in front of me dictating my speed.

However this quote confuses me even more.
Does cruise detect a vehicle already on roundabout coming from the right...don't think so... so yes if clear no need to slow down(assuming you ain't going at 70mph) however if there is a vehicle on roundabout then YES I would assume everyone would slow down!!
Again your comments need explanation???

 

[robnchris]

Ok robnchris . I accept you are not travelling at 70mph even tho you have that set on cruise.
I certainly would not be happy having the car in front of me dictating my speed.

However this quote confuses me even more.
Does cruise detect a vehicle already on roundabout coming from the right...don't think so... so yes if clear no need to slow down(assuming you ain't going at 70mph) however if there is a vehicle on roundabout then YES I would assume everyone would slow down!!
Again your comments need explanation???

Ahh Poppycamper welcome aboard at last, I am so please you have finally grasped the point that if you set 70mph on your Adaptive cruise control you will only travel at the speed (providing of course it doesn't exceed 70mph) of the vehicle in front of you.

Now to shed light on your confusion, No a vehicle with Adaptive C C will not see another vehicle coming from the right on a R-A_B.

So back to my E.G. as you approach the R-A-B with your Adaptive CC set at 70MPH you vehicle has registered that the car in front of you is slowing down thus your car will also slow down, keeping that safe distance between you both that had previously set in the vehicles settings.
Now then the car in front at the last moment without any warning or indications moves in to the right hand lane, your Adaptive CC instantly recognises that it has a clear road ahead.
Now then here's the rub......your car oblivious to the R-A-B and indeed also oblivious to the car that is currently on the R-A-B will unless you take evasive action collide at some considerable speed with both.

That's the thing about an automatic vehicle, they are automatic but you have to be there in an overall controlling position.
Hence me mentioning you have to be pro active.

I trust this clarify's the situation for you.

 

[kevenh]

It's not about a grasp of English language, it's about reading and interpreting what is written, E.G. being an example of what CAN happen...
The example is as explained, you have your CC SET to 70mph. Not that you are travelling at 70mph.(other speeds are available) obviously being an Adaptive CC system your vehicle will only be travelling as fast as the vehicle in front of you.
So approaching the R-A-B he slows down which means you slow down, I made the silly mistake that people reading this would naturally assume everyone slows down for a R-A-B.
The danger comes when the vehicle in front unexpectedly moves into the outside lane to turn right, your vehicle now sees a clear road ahead and accelerates.

If that is confusing then I apologise

Maybe poppycamper meant that by the point people are changing lanes to confuse your adaptive CC you left it too late to disengage it.

But I've never driven with an adaptive CC system. Do they get you safely a round a roundabout engaged?

So you ARE describing having an adaptive CC system enabled up to the point that at an approach to a roundabout, it reacts to cars ahead that are changing to the lane they need?
Turn off adaptive CC system earlier

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[Northernraider]

My current van has a retrofit ( dave newell) cruise control on it ....i love cruise control in general but i find this one actually gains speed going down hills which ive never encountered on any previous vehicles with factory fitted cruise .

I always set it around 62mph as its enough to pass trucks etc comfortably

But when going down hill ive seen it creep up to nearly 70mph at times and it shouldn't


P.s TinaL it wont put your brake lights on as it uses the engine to brake and not the brakes
Brake light switch is linked to brake pedal

 

[Dorset Diver]

ACC operates the brake lights as it uses both the engine and brakes to manage over speeds

 

[cmcardle75]

My current van has a retrofit ( dave newell) cruise control on it ....i love cruise control in general but i find this one actually gains speed going down hills which ive never encountered on any previous vehicles with factory fitted cruise .

I always set it around 62mph as its enough to pass trucks etc comfortably

But when going down hill ive seen it creep up to nearly 70mph at times and it shouldn't


P.s TinaL it wont put your brake lights on as it uses the engine to brake and not the brakes
Brake light switch is linked to brake pedal

Only some cruise control units are connected to the brakes. This is far more likely on a factory fit system where the manufacturer gets to design or specify the entire system, including the brakes. Retrofit systems are less likely to have braking capability as this requires integration with the complex ABS systems (unless the "retrofit" system is just adding the missing stalk to the pre-existing manufacturer system). Without this braking ability, the vehicle will gain speed going down steep hills.

 

[robnchris]

So you ARE describing having an adaptive CC system enabled up to the point that at an approach to a roundabout, it reacts to cars ahead that are changing to the lane they need?
Turn off adaptive CC system earlier

Kevenh, Adaptive CC like any other driver assist additions in your vehicle they are there to help (assist you) whilst driving on your journey but you have to be pro-active you are after all in control of the car.
The system is controlled by buttons on your steering wheel very easy to operate, you can adjust the speed up or down, so no need to turn if off just control your speed with your fingers instead of you right foot.

I personally think Adaptive CC is brilliant, it makes you think ahead of the road conditions, be more aware of the other vehicles around you, mind you being a motorcyclist I,m always conscious of other vehicles.

 

[Northernraider]

Only some cruise control units are connected to the brakes. This is far more likely on a factory fit system where the manufacturer gets to design or specify the entire system, including the brakes. Retrofit systems are less likely to have braking capability as this requires integration with the complex ABS systems (unless the "retrofit" system is just adding the missing stalk to the pre-existing manufacturer system). Without this braking ability, the vehicle will gain speed going down steep hills.

Ive never yet had a vehicle with cruise control that was fitted to the brakes , my vw T4's , passat cc , merc e220 , bmw 520 , 318, 328 all simply used the engine braking .... certainly none activated the brake lights......i think ACC is fairly new and may be different as it will automatically guage the speed of vehicles in front etc .... none of mine ever had that but the newest vehicle ive had was a 2013 Renault captur.
None ever activated the brake lights when on cruise but none ever went above the set speed either as thats pretty much the job of cruise control to maintain the set speed.

Thats why i made the comment as this is the only vehicle ive ever owned that the speed increased going downhill while on cruise control.

But it is the only one with retrofit non factory supplied cruise

I fitted cruise to 3 of my t4 vans but simply a case of fitting and plugging in the stalk and then activating via ecu

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