Cruise control and fuel consumption

powermzii

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I have done a search but haven't been able to find an answer - Does using cruise control on long journeys lead to improved fuel consumption? I know the manufacturers might say yes but what have normal users on the road found?
 

ID_10_T

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On a level road cruise control will help with fuel efficiency but when there are a few hills it would want to stay at 120km/h
 

Jola

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On a level road cruise control will help with fuel efficiency but when there are a few hills it would want to stay at 120km/h
And then your fuel consumption will be worse !
 

Sn00zE

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Cruise control will use allot more fuel coz it will keep the petrol down to maintain the speed that you have set.. Your foot is allot better! I only ever use cruise control to just stretch my legs or for when your foot falls asleep.. Cruise control, I think, will only work best on an automatic car, coz there the car computer will change gears to maintain the speed not just step on the gas!
 

Mars

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Personally I find my fuel consumption improves with cruse control. Especially on long trips, not even taking into account those bastid speeding fines for going 135 in a 120 zone at the bottom of a hill... Bastids...
 

HapticSimian

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The guys who take part in the annual Total Economy Run don't use cruise control - if you know how to drive economically, you'll fare a little better than a car's computer because you can see the road ahead & adjust your inputs accordingly. As has been mentioned, the cruise control can't do anything more than mash the accelerator in an attempt to maintain speed.

That being said, the convenience & lack of speeding fines is worth a teeny penalty in consumption as far as I'm concerned.
 

LCBXX

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The comfort of having cruise control by far outweighs the very slight impact it has on fuel consumption.
 

herbertk

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I use CC when doing long trips depending on the speed you dial in it can be worse if you would (theoretically :) ) set it to 140 or 150 then it is worse than doing this speed without CC but at 120 it is better
 

Robocop

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Mine improves when using cruise control. Just stick it 6th gear and relax. The extra fuel used on inclines are offset by using so much less on level roads and declines.
I once did a round trip to Phalaborwa and back to Joburg on 65L of fuel. That's a average off 18.5km/l. I don't think I would have been able to do that without cruise control.
 

Nerfherder

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We have a meter on our Suzuki that tells you how your consumption is being affected while you are driving. Its got km/l so the higher the bar the better (more KM per liter).
The car also has 6th gear and cruise control.
You have to be very careful with the cruise control because you need to make sure that you always have enough power in the gear. If you are in 6th gear and going up a lot of steep hills then its not going to be very efficient as the cc will always be accelerating to maintain your desired speed.

The ideal conditions for cc are a straight, flat road with very few cars. Then you can go in to top gear and set your speed to 129 and your rev's will be just under 3000. Also if you have to overtake then switch down a gear till you have the power, overtake, get to your desired speed and gear and then resume cc. Often I made the mistake of resuming cc while not having enough power, this wastes a lot of petrol
 

Robocop

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My car does not feel hills in 6th. I have 385nm from 2100rpm. Even with a trailer and AC on it just shrugs off the inclines.
 

Ou grote

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Personally I find my fuel consumption improves with cruse control. Especially on long trips, not even taking into account those bastid speeding fines for going 135 in a 120 zone at the bottom of a hill... Bastids...
True, :) that's why I use it, even though it costs more.
It's very handy in the South Cape in particular with all their cameras.

If I was using my foot, I'd drive faster than 130km/h.
 

herbertk

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Mine improves when using cruise control. Just stick it 6th gear and relax. The extra fuel used on inclines are offset by using so much less on level roads and declines.
I once did a round trip to Phalaborwa and back to Joburg on 65L of fuel. That's a average off 18.5km/l. I don't think I would have been able to do that without cruise control.
Mine is auto CC make so much more sense...
 

MFour

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I have an auto, and using CC does give me slightly better fuel consumption. Even if it did not, as was mentioned, the comfort of not having to constantly check yourself far out ways any negative it might have.
 

powermzii

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Am doing a trip from CTN-PE and back at the end of June and been pondering on whether there would be any advantage. Going to try and see if i can make it on one tank (2.3l Mazda6 with 66lt tank - 750 odd kms), will try one way mostly with CC and the other way without and see how it goes.
 

Waaib

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I have a 3.7L Automatic Jeep. I use cruise control all the time, even to work and back, and average 14.4L/100. When I drive without cc it averages 17.5l/100.
 

Frankie

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The effect is going to vary from driver to driver, but the use of CC is more economical for most drivers because it keeps a constant speed verses the driver making frequent throttle changes.
The convenience would be worth it for me, even if it meant a slight dip in economy.
 

Shake&Bake

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I've got an automatic and the CC really comes into play on the long road.

On a drive to PE last year from CPT, I used it quite often, keeping it at 140kph, but only on long straights with no inclines.
CC consumes a heck of a lot more on inclines, so when approaching hills, I'd just give it some juice on my own and then tap off till I reach the top and then hit the CC again.

I find myself using CC quite a bit on the M5 when driving to and from work and it does reduce the consumption on that stretch too at 100kph.

CC really does help when I my foot gets weary, but leave it on for too long and then my mind gets tired and I feel like dozing off behind the wheel, as all I'm doing is pointing the car in the right direction. Then it's back to good old footy action :p
 

Colin62

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Depends on the car to some extent.

I could easily beat the cruise control on my Mini Cooper, but I have to be very careful to come close to the one in my Merc. The Mini was set for performance, and would put full throttle to keep the speed up without hesitation, while the Merc is a bit lazy - it is happy to drop speed by 10-15 km/h up a hill, and pick it up again at the top. I often find myself 'helping' it a bit on hills.
 
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