Cruise Control

[powza]

As I've only had my VTR+ diesel for a few weeks I am still getting to grips with all the various bits and pieces. Never having had a car with cruise control before, I am finding this really good when doing motorway driving. Does anybody know if using cruise control has any effect, positive or negative on MPG?

 

I would have thought that if selected at 65 or 70 mph, this should maximise MPG as you are not accelerating and decelerating all the time. I haven't a clue about technical issues, however, and still don't understand why having the air con cuts your mpg.

[Ciaran2903]

and still don't understand why having the air con cuts your mpg

 

I think it is do do with the energy it uses, and the fact that the engine ends up charging the battery and therefore has to charge the battery more often.

 

But that is only based on what i think! :huh: I dont have anything to back it up! It just seems to make sence! :P

 

Not sure if the cruise control effects MPG, i would amagine so, but only slightly.

 

I do know that it is more efficient to have the air con on after 50MPH and anything slower it is more efficient to have the windows down, and this time its proven, not just me thinking! :P

 

I love using the cruise control, came back from brighton on the dual carriage way, set the cruise to 75MPH and had it on for about 15 mile straight! :D Just need that armrest and it will be great on long hauls!! :D

[Stuey]

I have found that it is a lot more economical than me actually driving the thing!! :P

[wozza]

The reason the aircon has an effect on MPG is because it uses the engines power to run it thus if your travelling at 30 with the aircon off the engine will only use a small amount of power with the aircon on it has to use more power to keep the compressor and a few other bits and pieces running.

 

Some cars its very noticeable and you actually can feel the drag on the engine.

[pork_pie]

Yeah I'd go with that.

 

THe drive belt powers the air con compresor and when in use creates a bit off drag hence a bit more fuel is used when the air con is activated

 

Don't believe them tree huggers who say air con is a bad thing and drinks juice. On average theres a 3-5% mpg penalty - which is a lot less than having the windows down and a tiny price for comfort (Citroens are fuel efficient vehicles end of).

 

Anyway if one has air con, the onus is on the owner to keep it running at frequent intervals otherwise the lack of use will conk out the system altogether and that means big bills.

 

In my experience Cruise saves petrol provided the conditions are favourable. No point using it in Brecon Beacons or Peak District or in rush hour traffic.

 

At 70 mph the diesel engine is spinning at just over 2000 rpm whish is a shade over peak torque which is most efficient point of engine speed.

 

Wish I had it on mine.... :P Great feature to have.

 

Its banned in Belgium.

 

Pate eating freaks

[evilone]

Yes using cruise control will improve your MPG.

 

Drive your car at 40mph in 5th gear, then switch on cruise control. you will see a drop in the revs. Less revs = better MPG.

 

When in motion all of the cars energy comes from the engine. It is not just air con that effects MPG but anything else you switch on when driving. The alternator and air con compressor take energy from the engine so the engine has to work harder to maintain the cars speed and power lights, radio, windows, air con and anything else I have not thought of.

 

Just running the engine and nothing else is how the official consumption figures are achieved.

[evilone]

Its banned in Belgium

 

You have to be joking! What if you buy a car in another country do you get arrested for switching it on?

 

I bet they don't ban the jet engine (a well known fuel efficient and non polluting means of power) there.

[Ciaran2903]

Wish I had it on mine....  Great feature to have.

 

What is banned?? Cruise control?!? :P

[pork_pie]

Yeah apparently so.

 

Nethalands has a similar silly rule with Cruise control.

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Back to Belgium there were cases where people slept at the wheel whilst having cruise control on.

 

Just think a lot of our decisions are made in that country. Makes you wonder don't it

[powza]

Cheers for the comments everybody :P

[Johndouglas]

Yes using cruise control will improve your MPG.

 

 

 

 

 

 

But only on the flat. Keep the cruise on as you come to a steep hill, and the pedal will floor, using much more fuel than if you changed gear and dropped the speed slightly. Even more so if you happen to be pulling a trailer.

 

The aircon effect on consumption is more marked on a smaller capacity engine than a larger one. During the early 90's I had a 1.7 BXTZD fitted with aircon which increased fuel consumption by about 5%. When I moved on to a 2.1 Xantia, aircon had little effect on consumption. My C5 seems to be the same.

[billynibbles]

Yes, I'm with johndouglas on this one. Cruise control is only any good for keeping your speed constant on the flat. Any decent driver who can spot an uphill run a mile away will improve on the efforts of c/c by building up some speed in advance (on a downhill, maybe) to avoid flooring the pedal on the up-gradient. Cruise control isn't that clever.

 

I thought I read last week that it's only illegal to use c/c in Belgium on busy roads. Of course, like the UK, that could be all of them!

 

It was in an article about all those things you need to know about driving in different countries (spare prescription glasses, spare bulbs, warning triangles etc. In one of the Balkan countries, even your front seat passenger's not allowed to be drunk. Others even have rules about keeping your car clean!)

[Ciaran2903]

In France, if someone flashes you, it means they are taking priority! That could get nasty! :P

[hertsnminds]

In the Netherlands people joining a roundabout have priority over those already on the roundabout.

 

Great fun the first time you find out :P

 

Ian

Black 55 VTR+

[wozza]

The dutch also all drive like idiots which doesnt help things.

[Ciaran2903]

The dutch also all drive like idiots which doesnt help things.

Dont the Dutch also have a book, which lists all the number plates of cars on the road along with the drivers adresses? I could have done with that a couple of times :D

hmmmm.............and, you could get a fit girls contact details :D :P