To cruise or not to cruise

[Terbs]

Straight question, chaps and chapesses.........

What is the most ecnomical type of driving....Self or cruise control !!!!!!!!

I had always assumed cruise control would be best, but it seems when I knock it off, the screen seems to give me a better readout
I have not put this to the test on a motorway yet, but as I have to go to Brackley every Monday, I shall have the oportunity to test.

And before TB comes in with a wisecrack...yes I do know which button to press..........(well, most of the time)

[Kevin Wood]

It's the same engine hauling the same car, cruise or not. Not worth wasting your life worrying about it, TBH, because the difference will be minimal.

At least on cruise you aren't tempted to gradually increase speed, which can be a problem with a V6, since 70MPH is no less noisy than <mumble> MPH.

Then again, cruise can't anticipate hills, so might be worse then as it has to change down late.

Swings and roundabouts.

[tunnie]

I'm lazy, so use cruise. Balls to fuel use! 

[Andy B]

Agreed with KW.
The trouble with cruise is that if you knock it off for whatever reason, it's too numb to accelerate gently till it reaches the previous speed. It has to get you back NOW! And that uses more fuel than if you gently accelerated back. Over a journey though, the difference would be minimal and once set, you don't then need to look at your speedo to check. 

[tunnie]

Will add the other problem with Cruise is you pull out to overtake, guy in front will often speed up and slow down where you are a constant speed.

[aaronjb]

The trouble with cruise is that if you knock it off for whatever reason, it's too numb to accelerate gently till it reaches the previous speed.

How do you get it to 'resume'? The manual talks about it, but I've never been able to get that to work in my car.. it appears all I can do is 'set current speed as cruise', 'cancel cruise' or when cruise is active speed up/slow down..

Tunnie's point is very valid - I've had that so many times on the M40 and it drives me absolutely bonkers.

[omega3000]

Throttle response is much better using the stalk buttons but not as good as the carlton manual box .

[Kevin Wood]

The trouble with cruise is that if you knock it off for whatever reason, it's too numb to accelerate gently till it reaches the previous speed.

How do you get it to 'resume'? The manual talks about it, but I've never been able to get that to work in my car.. it appears all I can do is 'set current speed as cruise', 'cancel cruise' or when cruise is active speed up/slow down..

With cruise cancelled, the "slow down" button will resume the last cruise control speed selected. You need to be doing around 20MPH or more for it to kick in from memory.

[Terbs]

Hmmmmm, very interesting points

I will say, that getting on the M40 at Wycombe and going up to M42, I set at 70mph, and by the time we got to M42, the range readout had incread by a fantastic amount....I mean a few hundred miles !!!!!!! Obviously, I thought this must be economical sense. The motorway was quiet, so I did not have to vary much
But coming back from Brackley on Monday, the cruise was set, and seemed constant at 30mpg, but when I knocked it off, I seemed to have a readout of up to 38mpg steady....dropping for uphill, and rising dramatically for off throttle, whereas on cruise, the going downhill consumption did not drop as much, and never up to the 999mpg you get when coasting

Hope that made sense

[aaronjb]

The trouble with cruise is that if you knock it off for whatever reason, it's too numb to accelerate gently till it reaches the previous speed.

How do you get it to 'resume'? The manual talks about it, but I've never been able to get that to work in my car.. it appears all I can do is 'set current speed as cruise', 'cancel cruise' or when cruise is active speed up/slow down..

With cruise cancelled, the "slow down" button will resume the last cruise control speed selected. You need to be doing around 20MPH or more for it to kick in from memory.

I'll try that again next time I'm on the motorway  I'm sure that's what I was doing.. or maybe I was pressing the 'increase speed' button 

[Terbs]

You got me thinking now about the 'resume speed'....I'll try that Saturday....I'm off to Swindon for a few days down the M4 Cars will be idle till then

[brendan1983]

Cruise will use more fuel - however the difference will be minimal... You'll notice more of a difference in an area with lots of hills/long gradients.

Best is to allow the car to speed up slightly on downhill sections and then allow it to slow gradually with a fixed throttle position.

[henryd]

Older cruise systems are not so good,my disco is vacumn/mechanical and you can feel the throttle pedal going up and down much more than it would if I was driving normally,DBW systems should be much better

[05omegav6]

Never seems to get much over 165mpg on overrun in top, drop a cog, foot off throttle and straight up to 999 guess that in top the engine has to 'work' in order to compensate for less available torque below 2000rpm

The MK3 Granada system was a Vacuum/mechanical system. Was a bit strange when you set a speed because the system used to pull on the throttle cable, pulling the pedal down and away from your foot. DBW, being ECU controlled doesn't do this and also doesn't seem to control downhill speed anywhere near as well as the old Ford set up (found this to be the case in the Vectra C as well).

[Kevin Wood]

Never seems to get much over 165mpg on overrun in top, drop a cog, foot off throttle and straight up to 999 guess that in top the engine has to 'work' in order to compensate for less available torque below 2000rpm

The MK3 Granada system was a Vacuum/mechanical system. Was a bit strange when you set a speed because the system used to pull on the throttle cable, pulling the pedal down and away from your foot. DBW, being ECU controlled doesn't do this and also doesn't seem to control downhill speed anywhere near as well as the old Ford set up (found this to be the case in the Vectra C as well).

999 MPG means it's in overrun cutoff. In top gear it may not be above the RPM threshold for overrun cutoff, hence the high (but not silly) MPG figure.

Not sure what the threshold is for a manual setup. It's around 1000 RPM for an auto, but can believe the manual config will set it higher to stop the engine stalling if you suddenly knock it into neutral.