I have seen it suggested that using cruise control improves fuel consumption.....
Others have argued that it increases fuel consumption by up to 10% or thereabouts.
Can anyone please give a justified explanation of whether cruise control does, or does not save fuel?Am I Gammon or Woke ? - I neither know nor care.
2016 Discovery 4 Landmark
2011 Mercedes Benz SL350 (R230)
1973 MG B GT V8 - 3.9L John Eales engine, 5 speed R380 gearbox, since 1975.
1959 MGA roadster - 1.9L Peter Burgess Engine - 5 speed gearbox
Past LRs - Multiple FFRs, Discos & a Series I - some petrol, some diesel,
none Electric or H2 fuel cell - yet.
There are 10 types of people in this world: Those who understand binary, and those who don’t.
I can't give any scientifically justified reasons but I use CC all the time and I get much better fuel consumption out of our D3 than SWMBO does who very rarely uses CC .
She doesn't use it for 2 reasons really:
1. she doesn't know how to operate it despite being told dozens of times
2. she's away with the fairies most of the time she's behind the wheel
Try playing the 'don't touch the pedals' game! Engage cruise control as soon as you can, even in town and then just use the +/- button to control your speed. See how long you can go without touching the brake or accelerator. It takes quite a bit of anticipation and forward planning - especially when it comes to slowing down cos when you've got an auto, you don't get much in the way of engine braking to help.
Anticipation and forward planning are not SWMBO's forte For example, on dual carriageway, doing 70 - lorry up ahead doing 55 ish. She's away with the fairies as usual so rather than checking the rear view mirror when we're some distance away in order to plan overtaking, she waits until she is forced to slow down before checking it's clear to overtake. Drives me nuts I'm glad she doesn't like towing the caravan - we'd be in the car twice as long and use twice as much fuel with all the slowing down/speeding up she does Now an ex-D3 owner after 7 happy years. Miss the car but not the big bills
19th May 2009 10:12 am
Roel
Member Since: 16 Aug 2008
Location: home
Posts: 1215
Try to drive as constant as possible is the key. I think you can do that better yourselves than the CC.
I think you will save fuel. At least I think I do but then it is also speed depending and I am not always driving the same speed.Roel
1997 Camel Trophy Disco ex-P101JWK (traded it for a Britains 42101)
1984 90 TD5
2005 G4 Disco 3 BN55WPT
Also member of club MTR
and Club Faultmate
Interested in my 4x4 history see my website: www.mudmachine.webklik.nl
Sorry it's in Dutch and with google translator it gets funny.
She doesn't use it for 2 reasons really:
1. she doesn't know how to operate it despite being told dozens of times
2. she's away with the fairies most of the time she's behind the wheel
Exactly the same as my missus, are they all the same
I don't know about fuel consumption but use CC as much as possible, expecially in France. Big wide, quiet motorways, heaven. Worth every toll.
19th May 2009 2:25 pm
adam
Member Since: 20 Sep 2005
Location: Home and Happy
Posts: 6917
Anecdotally, CC seems more economical
19th May 2009 2:28 pm
Ken
Member Since: 20 Feb 2006
Location: Here
Posts: 10865
Nah the trick for france is to drive thru it as quick as possible
Nah the trick for france is to drive thru it as quick as possible
At least you can drive through it quickly as opposed to our clogged up roads
19th May 2009 2:31 pm
shopbobby
Member Since: 08 Mar 2008
Location: Herefordshire
Posts: 166
Ken wrote:
Nah the trick for france is to drive thru it as quick as possible
Whilst throwing as much litter out of the window
And running a good tank of Redex treated fuel to burn off all the crap into the atmosphere...RLD Sump Guard & Spare Wheel Protector, 19 GoodYear Wrangler, 17in Maxxis Bighorns
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19th May 2009 2:31 pm
wvlenthe
Member Since: 07 Jan 2009
Location: Arnhem
Posts: 1967
Roel wrote:
I think you can do that better yourselves than the CC.
Yes you can. And you can do something else better too: looking ahead. Especially in hills/mountains, you can choose to take your foot off when nearing the top, whereas CC will keep on applying power until exceeding set speed on the way down.
Having said that, you need to drive very concentrated to do it better than CC. Anything distracting (distraction season coming up now, especially when high-seating in a D3) and speed will go up and down. I've given up trying to beat CC and use it all the time, also in town (50 kph) and as often as possible on motorways.
btw Albourneboy; I do play the 'don't touch game' as well and use command shift for engine braking then.
regards,
WiljoD3 V8 HSE Auto in Zermatt silver - driveway version gone but not forgotten, only the living room cupboard version remains
19th May 2009 6:11 pm
landyhead
Member Since: 19 Mar 2009
Location: cardiff
Posts: 144
Albourneboy, my swmbo and yours related,mine wont even listen ,says the dont touch game is dangerous,
as in are you going to brake any time soon.
As for terrain response and low box, think she thinks their front machine guns and passenger seat eject.
Any way find dont touch and cc works for me, also use command shift for engine breaking on steep hills.welsh petrol head
Base 5 seat, ex HA with air,terrain,tip tronic and some bling (gone)
D4 Gs 7 seat totally standard for now
Frankly I find your comments offensive and sexist...
There are many SWMBO's who can use CC, terrain response and low box... really!
Personally... I find the fuel economy better when not using cruise control.As you slide down the banister of life
may no splinters point your way
Disco XXV
RRS2 Autobiography Dynamic MY16
Discovery Sport HSE Lux MY17
Evoque HSE Dynamic MY16 (Gone)
RRS2 Autobiography Dynamic MY14 (Lovely car but preferred the Disco!)
Disco 3 Tdv6 HSE MY05 (owned for 11 years and now gone)
Range Rover Sport HSE MY11 (Gone)
Freelander2 SE (Gone but the most reliable car we've ever owned)
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19th May 2009 9:44 pm
Roel
Member Since: 16 Aug 2008
Location: home
Posts: 1215
I sometimes use cc and sometimes not. Not using CC gives me something to do when I drive and to work.
I drive between 800 and 1000 km to go to work so sometimes it gets boring on CC.
Otherwise I just start chasing Germans that flash at me, just to proof that 300 hp is enough to go fast uphill.
I am playing with sport mode too. It looks like that isn't bad for fuel consumption either for me.Roel
1997 Camel Trophy Disco ex-P101JWK (traded it for a Britains 42101)
1984 90 TD5
2005 G4 Disco 3 BN55WPT
Also member of club MTR
and Club Faultmate
Interested in my 4x4 history see my website: www.mudmachine.webklik.nl
Sorry it's in Dutch and with google translator it gets funny.
19th May 2009 9:51 pm
zaphod
Member Since: 18 Sep 2007
Location: Magrathea
Posts: 357
I think the mk1 human foot and eyeball is best (as other have pointed out, by accellerating before you're on the hill and lifting off before you're over it), especially in hilly, twisty roads - but for ease of use and ensuring youre not (too far) over the speed limit, the CC wins hands down.
It lets you concentrate on lots of other things going on, rather than focussing on keeping the speed bang on.
TBH, I don't think it could make more than 1 or perhaps 2 mpg difference
As Albourneboy suggested, drivers who don't plan ahead will have increased fuel consumption, compared to those that do, no matter which sex they are or whether thay are using CC Sail Fast - Live Slow...
I once did 1200 kms in one day on cruise control with only 1 setpoint re-set (quarantine checkpoint). With no hills and a few wide bends in the road, but a camp trailer on back got 15.0l/100km on a V8. It was the best mileage of the entire 7000 km holiday and also the fastest leg. Maybe someone in the UK or Europe can replicate this test Jim Dowell - D4 HSE TDi, 12,000 hydraulic winch & hidden winch mount, MTRs, TyreDog, Traxide 2 x aux battery system, fixed air compressor, Dolium roof rack, MitchHitch.
RIP 2005 D3 HSE V8 5 seater gold (stolen and torched)
20th May 2009 3:32 am
wvlenthe
Member Since: 07 Jan 2009
Location: Arnhem
Posts: 1967
Quote:
Maybe someone in the UK or Europe can replicate this test
@Roel
I have tried and according to the trip computer, using sports mode takes about 5% *more* fuel in my case.
regards,
WiljoD3 V8 HSE Auto in Zermatt silver - driveway version gone but not forgotten, only the living room cupboard version remains
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For example, on dual carriageway, doing 70 - lorry up ahead doing 55 ish. She's away with the fairies as usual so rather than checking the rear view mirror when we're some distance away in order to plan overtaking, she waits until she is forced to slow down before checking it's clear to overtake. Drives me nuts 
I'm glad she doesn't like towing the caravan - we'd be in the car twice as long and use twice as much fuel with all the slowing down/speeding up she does 
