Hi all,
I've just borrowed a car that has the fuel consumption displayed in L/100Miles.
What number do I multiply or divide by to display MPG?
Thanks in anticipation ....
Regards ..... Robert
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Presumably it's litres / 100 km?
In which case divide 284 by the l/100km to arrive at MPG.
Not easy to do in your head!!
Richard
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Hi,
No, its litres per 100 Miles!
Regards
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Robert,
My addled 60 plus year old brain can't cope with all this so, I bought a Sharp metric conversion calculator. It cost, I think, less than a tenner and converts all this funny metric business into my familiar imperial units. My vehicle odometer is in KM's so it's invaluable for my MPG checks.
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More or less 10litre/100km is 28mpg (28.4 if you wish).
If you want to do quick checks as you go along, that should give you enough to work it out in your mind.
i.e. 5l/100 km is half and therefore double 28 is 56. I'm sure you get the idea. What else are you going to do in a traffic jam !
If you are doing accurate checks than of course you can use a calculator.
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As a start, we should dispense with "miles per gallon" - it will be hard, and we shall have to think of a new magic number instead of 40 or 36 or whatever. It looks as though we are stuck with the miles, but there are precious few stations which still sell fuel by the gallon. Why buy by the litre and calculate economy by the gallon?
OK, so I know it is inconsistent to use a metric/imperial hybrid, but let's try miles/litre for a start. A good figure for a diesel is 12 m/l (=54 mpg) and for a petrol 9 m/l (=41 mpg).
If you are unlucky to use litres/100km, then that is the same as litres/62 miles. For the diesel that does 12 m/l, that is 60 miles/5 litres, or about 5.2 l/62 miles or 5.2 l/100km.
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Could be wrong but
4.546 l = 1 gallon
Therefore, Y being mpg
Y x 4.546 = gallons per 100 miles
y x 4.546 /100 = gallons per mile
Therefore mpg = 1/(Y x 0.04546)
Could be very wrong indeed. Let us know what figure you come up with!
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sorry Y should be L/100km
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damn. This is really annoying me now. I have forgotten to convert Km - miles and still the figure comes out wrong.
damn.
this is friday afternoon sorted out - I'm not going to rest until I get a simple figure!
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done it! brain a bit slow today
10 l / 100km
=
0.1 l / km = 0.16 l per mile = 0.0351957 gallons per mile
1/0.0351957 = mpg = 28.41 mpg
Therefore to convert l/100km to mpg take your l/100km figure as Y and plug it in the sum below
1 / (Y x 0.0035195)
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Therefore to convert l/100km to mpg take your l/100km figure as Y and plug it in the sum below
1 / (Y x 0.0035195)
Therefore to convert l/100miles to mpg take your l/100mi;e figure as Y and plug it in the sum below
1 / (Y x 0.00219973)
Therefore 10l/100m = 45.46mpg
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So, as closely as we need to know it while we're doing 80 on the M25 (!!), the sum is mpg = 450 / Y .
Thus, when Y is 15, mpg is 30 and when Y is 10, mpg is 45.
The aim, then, is to push Y as low as possible; when it's more than 15, Gordon has his hand in your pocket, whereas you can relax (comparatively) if you can get Y to below 10.
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CM
I programmed this in my calculator many moons ago as:
100/(miles/gall x 0.354) = litres/100km
It looks odd, but the equation has to account for the fact that high mpg = low l/100km
Regards
John S
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Robert, I think this is correct
10 L/100 miles
=2.203 gall/100 miles
=0.022 gall/mile
=45.45 miles/gall
45.45/10=4.54, so to get mpg from L/100 miles, multiply by 4.5.
hth
Andy
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That works for 10L/100Miles, but using less fuel should surely result in a higher mpg - not a lower one?
Sounds like I'll have to write a table out ......
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Gentlemen,
Having once succesfully completed this, I know I'll never try it again!
You have my sympathies.
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10 litres/100 miles = 45mpg approx
15 litres/100 miles = 30mpg
5 litres/100 miles = 90mpg
Work out all other options quite easily
i.e 12.5 litres/100 miles = (45+30)/2 =37.5mpg
20litres/100miles = 22mpg
if you take 10 litres/100 miles as the base, then all variations are quite simple..
(my head hurts.. my degree in maths and physics was a LONG time ago:-(
madf
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That works for 10L/100Miles, but using less fuel should surely result in a higher mpg - not a lower one?
Quite right, I am wrong
Sounds like I'll have to write a table out ......
Might be easiest!
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The answers are
Divide figure in l/100km into 282.12, e.g., 7 l/100km = 40.3 mpg
Divide figure in l/100mi into 454, e.g., 7l/100mi = 64.9 mpg
Both figures are approximate and I worked them out ages ago, so don't ask me to justify them. I just know that they work.
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Robert,
Is it definitely, definitely l/100miles?? That's not a standard way of expressing economy, it's mpg OR l/100kilometres usually. Most strange...
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Hi Dave,
Yes. L per 100 Miles ......
Regards
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Litres per 100km is standard continental stuff where the goal is the 3l/100km vehicle.
What I want to know is, which manufacturer is so cheapskate that they can only adapt the chip to litres/100miles and nor proerly re programme it for the UK market?
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Work out how many miles per litre then multiply by 4.5.
So if 10 litres to do 100 miles its 10 * 4.5 =45mpg
If 12 litres per 100 miles its 8.5 * 4.5 = 36 ish mpg
Or did somebody just say all that? I'm easily confused (to use somebody else's line)
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Your numbers are right, but mine (see above, can't be bothered to repeat 'em) do the miles/litre conversion for you though.
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Mazda - the new 6 ...........
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