Does Cruise Control imkprove Mpg?

[Leander]

I amazed myself yesterday by fixing the cruise control on my 75 CDT.

Yes, it was only moving that impossibly-hard-to-reach switch behind the clutch pedal, but it was a big job for me!

Anyway, took the car out for a spin, put on cruise, and noted an immediate improvement on the mpg readout.

Now I know the message centre mpg figures are not to be treated as accurate, but there was still a clear relative improvement, of approx 2-3mpg.

My right foot is very light, so I can't attribute all the improvement to that - or maybe I should...

So is cruise always more economical than 'manual' driver control?

Over to you, the experts....

[Kearton]

Hi Leander,
I'd expected it to initially but I can't say I've found any significant difference on mine, also diesel. It just makes long drives a bit more relaxing and helps keep the speed cameras at bay on temporarily reduced speed sections.

Cheers,
Kearton

[StevenWilliams]

It all depends on how good a driver you are in the first place..

If you have good clutch control and normally change gear at the correct times then you'll not notice a great difference.

The lower down on the scale you are the more difference it will make.

[JohnDotCom]

On Automatics it seems to improve MPG slightly.

[Leander]

Sorry John, should have made it clear I'm driving a manual.

In regard to Steven's point, I think my clutch control is okay - I try to get it up the gears as soon as I can, but never before the engine says its ready.

I thought maybe there was something about how fuel was fed to engine when cruise was on, that might improve mpg - but I'm obviously speaking as a total layman.

[JohnDotCom]

Unless you watch the speedo or can tell as many say they do, (speed cameras disprove that though )
you generally use slightly more fuel due to speed not kept at a exact constant,
unlike cruise control that will stick to whatever you set it to.

[BigRuss]

On the diesel CC is very smooth as it's drive by wire with a gradual resume when required. I find to have slightly better fuel comsumption using it.

On the V6 the cruise isn't as smooth and I don't find much difference in fuel comsumption.

The only thing to do really is give it a try and see what you find mpg wise, and you may find you don't like driving with CC some people don't.


Russ

[Leander]

Originally Posted by JohnDotCom

Unless you watch the speedo or can tell as many say they do, (speed cameras disprove that though )
you generally use slightly more fuel due to speed not kept at a exact constant,
unlike cruise control that will stick to whatever you set it to.

I don't watch the speedo, I try and watch road

- so maybe what you say is the answer John! That said, I wonder if it would make 2-3mpg difference though. Of course until or unless I do a 'precise' test, on a certain piece of road for a certain distance, that improvement in my mpg is only approximate anyway.

[James.uk]

If you bear in mind the fact that you can only use CC on a fairly empty road, then even if it did make a differance, the amout would be very small.

I had it on my old Honda auto, and (A) using it gave me the creeps! And (B) I never got much chance to use it due to traffic..
..

[Leander]

Originally Posted by James.uk

If you bear in mind the fact that you can only use CC on a fairly empty road, then even if it did make a differance, the amout would be very small.

I had it on my old Honda auto, and (A) using it gave me the creeps! And (B) I never got much chance to use it due to traffic..
..

hi James,

Yeah, it felt pretty weird to me too at first!

Most of my miles are on the motorway, out of rush hour, so if it affect mpg positvely then I'll be using it frequently.