Why do we still describe fuel economy in mpg?

[boognish76]

We buy petrol by the litre and tank capacity is given in litres, so why, when it's very easy to work out 'miles per litre' ,do we still use 'miles per gallon'?

[gilf]

I would guess because its an accepted standard. Whats the MPG of a 72 for Beetle not sure but I'm sure you could find out, OK with a bit of calculation you could work out the MPL but its not as instant as having a standard rating. anything over 15-20 old would have a recognised MPG rating and that makes it easy for comparison. having said that depends if your using UK or US gallons.

[RCP]

Because U.K. gallons are a significantly larger unit of measure than a litre, it is a more "visible" difference. For example a car that does 40 mpg would have an mpl of 8.81 (approx) wheras 35 mpg would be 7.86 mpl. The larger the number the easier it is to grasp the approximate percentage difference ( 40 - 35 = roughly 12% less at a glance but 8.81 - 7.86 does not jump out at you so much. Or perhaps it's just me being old fashioned & conservative!).

[BenDToy]

Not really an answer but more an example of odd measures. The accepted metric fuel consumption is litres per 100 km. I had a Mazda with a computer which showed the fuel consumption in litres per 100 miles. It does make a sort of perverted logic - we drive miles and we buy litres of fuel, but I ask you....!

[darth vader]

old habits die hard. How many people on here are from the UK and still buy fruit/veg/meat in pounds and ounces?

[WendyW]

Got me there Darth Vader ..... I still think in pounds & ounces.

[KARL]

This is simply a question of "why are the British the odd ones out ?". When abroad, most Brits drive on roads covered with speed and distance signs in metric notation and there is not really any indication that they suffer spasms from dealing with this. There are small signs that Brits can adapt to international standards in Britain also - the most notable are decimalisation of currency and conversion from Farenheit to Celsius (the latter largely having won the competition, even among average people). Although hospital records are all in kg people still discuss their weight in stoneage terms. Some public figure was recently quoted as having said that the British are slowly "inching" toward the acceptance of km, and it is worth remembering that metrication was legislated for in education, industry, specifications and descriptions as long ago as the Sixties. Nowadays you do hear in the media metric terminology stated without conversion, I noticed this just a week ago when forest/moor fires were referred to as covering square kilometres and being so many metres away from buildings, etc. - I think the people battling them must operate in metric (probably to be able to co-ordinate with foreign services when necessary and the reporters simply did not know the conversion factors, so it went out on air). Internationally, Britain and the British are regarded with the same sort of affection as a dotty but dear old uncle and they think in consumption as litres per 100km and have absolutely no idea what a gallon (or a pint for that matter) is. The Americans are even more backward (bushels, etc.) but to complicate matters they have a variant of the imperial system unique to the USA.

[WendyW]

Good Grief Karl ... was there some point hidden in all that :0) or did it at least make you feel better once you had said it!

[KARL]

You are right, Wendy, it is somewhat convoluted - but then if such convoluted (and eccentric) ways were not used in this country to call a spade a spade not only would the answer have been much shorter but the whole question would have been entirely superfluous. Oh, yes, I felt it needed said - I feel much better now, thanks.