Does cruise control use more fuel?

System

mrbadexample wrote: »

This refers to single carriageway roads.

Paras 162 - 169 refer to overtaking in general as part of the general rules for using the road (para 159 - 203). Para 253 - 273 deal with specifics of motorway driving

mrbadexample

!!!!!! wrote: »

Paras 162 - 169 refer to overtaking in general as part of the general rules for using the road (para 159 - 203). Para 253 - 273 deal with specifics of motorway driving

Ok, so it's 253-273 you're after then?

C_Mababejive

Cruise control is pretty useless in the UK most of the time. Having said that,if you can go on a long uninterrupted motorway run,it should be more efficient as it keeps the fuel feed as constants as possible. even better if you set it to 60mph ish. The inside lane is the best place to be as the outside lane is the new inside lane.

cyclonebri1

Lum wrote: »

That was my point. I've done so much long distance driving that I now suffer from cramps when trying to hold the accelerator in one place for a long time. Then I end up varying speed or needing to stop and stretch the muscles.

As a result I save using cruise control because I don't have to do that. just put the CC on, feet up (not literally) happy days.

Mine also manages to keep a speed constant enough that you can't see the needle move. Only time it breaks from this is on steep downhills where you would end up accelerating even with zero throttle. CC can't apply the brakes for you. What it will do though is keep that throttle at zero until your speed has dropped back to your set value, so you still gain the fuel saving benefit of that hill, providing you don't brake.

At the end of the day, brakes waste more fuel than the accelerator. The accelerator ultimately converts fuel into movement, which is useful. The brakes convert that movement into heat, which is not useful.

Misunderstood then, , agreed, the killer to fuel economy is braking, after accelaration of course

laird

My personal experience is that Cruise Control does save fuel.
I suspect the reason why people think it increases fuel use probably goes back several years and to an earlier generation of technology.
With "fly by wire" technology being used in modern cars the system will be adjusting the electronic throttle many times per second, certainly more frequently than my right foot could ever hope to do. That means that while very infrequently on a particularly steep up or downhill climb it may need me to intervene and override the cruise control to optimise fuel economy I can rely on the car's computer to outperform me.
When I bought the car the dealer took great time to point out the cruise control as a speed compliance function, maybe if more people used cruise control the number of fines for speeding would fall. Maybe avoiding fines is a saving on top of fuel economy?
Relaxing your right foot is nice, of course in practice your right foot hovers over the brake pedal because with cruise control your eyes are on the road ahead rather than having to look down or indeed across to a speedometer. It is amazing how easy it is to maintain a constant speed as a result; particularly on a motorway you can easily move lanes removing the need to cancel the cruise control.
Like other drivers using cruise control I smile at those less fortunate manual control drivers as they stab at the right hand pedal then slow down and repeat this process mile after mile. That is bound to have a negative impact on their fuel consumption.
But it isn't that which I find most puzzling, often with the cruise control on I find myself overtaking traffic in the left hand lane of the motorway, I am in the middle lane and the outer lane is empty (I'm lucky to be travelling off peak) when a car will come charging up behind me but rather than taking advantage of the empty outer lane and going by they slam the brakes on and sit behind me until I pull in. At which point they press the accelerator and disappear into the distance leaving me wondering why?!!

cyclonebri1

Idiophreak wrote: »

G


Two options - one, just "hover" your foot over the accelerator - fine, but gives you really bad cramp in your leg holding your foot up like that for any period of time. Two, put your foot flat on the floor - good, but you don't feel you'd be able to react as fast if you needed to brake. I tend, therefore, to mainly use cruise when I'm on the motorway or similar - less chance of a deer running out and so on...

H'mm ok, :eek:, but you can also drive according to conditions which always means varying your speed on a constantly monitored basis, ie, "think about it".


I get cramp whether the foot is on the accelarator, on the dash or stomping a status quo riff

Still can't think about CC without flashbacks to that yank who prosecuted GM or whoever because he thought he could get in the back of his camper to make a cup of tea when the CC was engaged, manual didn't say he couldn't????????:T:T:T, only in America,

System

mrbadexample wrote: »

Ok, so it's 253-273 you're after then?

No. They amplify the general rules for driving not replace them.

If you only believe 253-273 are the only things that apply on a motorway (as you seem to be saying) then gawd help anybody on the same motorway as you.

Lemonade_Pockets

My two pennies worth:

Anyone who advocates overtaking at a snails pace is a berk who shows general lack of consideration to other road users and is only serving to make the road network more congested than it otherwise might be.

Regarding cruise control, if you are a real keen bean driving without is more economical for reasons discussed. For the average driver particularly on motorways (where the gradient does not alter that much or very gradually) i would say cruise is more economical. As most drivers will try and stick at 70 for instance and then look down a short while later to discover they've crept to 75 or 80 which obv uses more fuel. Those that can keep at 70 for miles on end are probably spending too much time looking at their speedo and not enough time looking at the road.

waynedance

Had my car for 8 years and fitted cruise to it 2 years ago (retro fitted from a top of the range model). I use cruise all the time and I get more mpg.

TighterThanTwoCoatsOfPain

+1 for slightly better but perhaps thats more down to me likely doing more overtaking / travelling quicker when not using it than it actually being "better"

All my "best" economy figures have been when using it.

I remember when the Mk4 Astra was initially released, one of the motoring Mags did a test on the "Cruise Control sucks your fuel" theory and found it was actually better..

Meh, who cares about 0.5mpg either way anyway!