extra weight = extra fuel?

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Thu 31 May 2007 22:27
extra weight = extra fuel? - scfc_151
Im just curious to know how much weight in the boot would make a significant difference to fuel economy

I carry a tool box around (always have) with around 15-20kgs and lots of people have said it would make a fair bit of difference.

I cant see it myself but just wondered if anyone knew how much extra weight would start to inrease consumption
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Thu 31 May 2007 23:10
extra weight = extra fuel? - TurboD
what about a head wind?, this adds to fule use, so always go down wind.
You need to be realistic, it is marginal. All things are relative and the size of vehicle is important.
In my old VW transporter I got 36/37 mpg whether it had 500Kg or 850 kg of loads, it did not seem to matter.
what did matter was how far the loud pedal was down.
but it never did less than 33mog or more than 42mpg. a 20 kg tool box is only 4 gallons of petrol, you would need a computer to work out the benefit of taking it out.
stop worrying and use the car for what you want, I do.
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Fri 1 Jun 2007 08:26
extra weight = extra fuel? - jc2
Any increase in weight must increase consumption as must any increase in electrical load(headlights on all the time)but whether it's measurable is another matter.Possibly the positioning of the weight could also change the aerodynamics of the car.
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Fri 1 Jun 2007 10:59
extra weight = extra fuel? - L'escargot
Well, the density of petrol is 737 kg/cu.m at 16 degC so 20 kg of tools is equivalent in weight to 27 litres of petrol. I'm sure I've proved something but I don't know what!
--
L\'escargot.
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Fri 1 Jun 2007 11:16
extra weight = extra fuel? - L'escargot
I'm sure I've proved something but I don't know what!


Yes I do. You can compensate for the tools by never filling the tank more than 27 litres from the top!

--
L\'escargot.
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Fri 1 Jun 2007 11:22
extra weight = extra fuel? - Hamsafar
Weight has the most significant effect when accelerating and braking hard, such as in race situations, or spirited driving. It won't make so much difference when cruising, or gently trickling around town.
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Fri 1 Jun 2007 11:37
extra weight = extra fuel? - Group B
I always have about 15kg of tools and site equipment in my boot. I think that if my car has a kerbweight of 1450kg, an extra 15kg will have an insignificant affect on fuel consumption?

Carrying two passengers at 75kg each I would expect to have a noticeable effect on consumption, as in low-powered cars it has a noticeable effect on performance. But I wouldnt worry about a tool box.
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Fri 1 Jun 2007 14:18
extra weight = extra fuel? - oilrag
Air resistance would have a much greater effect. Staying amongst the trucks at just below 60mph I can get 78 mpg, at 70/75mph that falls to the low 60`s.mpg.
Carrying a load on the motorway seems to make little difference, but stop start, around town it does.

All I carry ( minus load) these days are tire air compressor and an AA card.

I used to carry a massive tool kit years ago, sufficient to do anything at the roadside, but as I need the security of the relay componant of the AA as a direct consequence of modern car electronics, theres no point in my bothering carrying tools.
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Fri 1 Jun 2007 14:20
extra weight = extra fuel? - oilrag
*Tyre* air compressor that is :) ( sorry i`m tired)
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