Talk:Gallon
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"This definition is occasionally used in United Kingdom," So far as I'm concerned most people in the Uk above a certain age - let's say 45 - and many people younger still think in pints and gallons. There is a strong emotional attachment to Imperial measures. It's a lot more than occasional use - it's still engrained in the culture! Milk is still sold in pints 1 pint = 568ml) in all major supermarkets. I shall delete the "occasionally" unless I see convincing arguments no to. Sasha 23:41, 27 February 2007 (UTC)
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[edit] History
"The metric definition of exactly 4.546 09 L was adopted shortly afterward."
I don't know that this has ever been officially adopted as the definition, anywhere. But it certainly is at least quasiofficial in at least the U.K. and Canada, a conventional conversion factor that has probably been at least declared to be good enough for legal purposes. Note that some lists of conversion factors such as The Units of Measurement Regulations 1995 of the U.K., do not claim to present any new definitions, but are rather merely compilations based on preexisting law. If you take them as official redefinitions, then the U.K. must have a weird definition of the hour, with a nautical mile defined as 1853 metres and a knot defined as 0.51477 metres per second (the actual legal definition of that nautical mile remains 6080 feet, notwithstanding the Units of Measurement Regulations 1995—note that the corresponding values for the international nautical mile are 1852 m and 0.51(4) m/s with the part in parentheses repeating, fours forever, no sevens to be found).
However, this statutory instrument may well be the one in which the 4.54609 litres became the quasi-official value for the United Kingdom. Before that, and going back into the 1970s at least, this value had been at least quasi-official in Canada, but the quasi-official value in the U.K. was different: 1 gal = 4.546092 litres. This distinction between a Canadian gallon and a U.K. gallon can still be found in many online lists of conversion factors, and in conversion programs which can be installed on computers.
Australia and New Zealand and other places may have similar lists of conversion factors in association with their metrication, but I don't know exact values, official status, or effective dates.
Gene Nygaard 05:50, 31 Dec 2004 (UTC)
- NIST gives 4.54609 L/gal as the exact conversion factor for both the "UK and Canadian" imperial gallon(s) (Ref: Guide for the Use of the International System of Units (SI) - NIST Special Publication 811). The Canadian definition matches this and can be found at Weights and Measures Act, R.S. 1985, chapter W-6. Dunno about the UK. I've never seen the ...092 definition.
- Urhixidur 15:32, 2004 Dec 31 (UTC)
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- The Imperial gallon was redefined in 1963 to the values that Benoit determined in 1898. This replaced the 1824 definition that had been in force. The gallon can be determined from the definition as M.(b-a).l/(b*(w-a)), where M is 10 lb, b, w, a is the densities of brass, water and air in the act, and l is the conversion from mL to c.cm, ie l cu cm = 1 mL.
- Putting l=1.000028 gives 1 gallon = 4.5460918785. Since l is variously this or 1.000027, it is prudent to round the gallon accordingly to 4.656092 or 4.54609, the latter is adopted in 1985 in the UK, and somewhat earlier elsewhere. Wendy.krieger 10:21, 18 September 2007 (UTC)
[edit] U.K. 1963 redefinition
The millilitre and the cubic centimetre were not the same in 1963. Were the densities in the 1963 redefinition specified in g/mL or in g/cm³? Gene Nygaard 11:47, 4 August 2005 (UTC)
Re the 1963 U.K. definition given here:
"In 1963, this definition was refined as the space occupied by 10 pounds of distilled water of density 0.998 859 g/mL weighed in air of density 0.001 217 g/mL against weights of density 8.136 g/mL."
Were these densities actually per millilitre, or were they per cubic centimetre? Note that the two were not the same thing in 1963. Gene Nygaard 05:55, 31 Dec 2004 (UTC)
[edit] Ambiguous gallons in 'mpg'.
Many articles mention 'mpg'. This is ambiguous. What do people think is the best way to disambiguate this? For example we could say:
- 15 US mpg
I think this is the 'least bad' solution. - 15 mpg (US)
I would prefer this solution because the 'US' is put near the gallon. Unfortunately, the context often requires more parentheses. For example 15 mpg (US) (16 L/100 km) - 15 mi/USgal
Hmm
Thoughts welcome. Please look at article examples to see how this would work in practice. Bobblewik (talk) 12:55, 20 Jun 2005 (UTC)
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- 15 mi/U.S. gal
- 15 mi/gal (imp)
- If in running text, not just in tables, "miles per imperial gallon" or "miles per U.S. gallon" in first instance, and one of the abbreviated versions thereafter.
- If any of them should happen to be used with boats or aircraft, ambiguous miles maybe should be disambiguated as well. I don't see that as much of a problem and can't think of any place where that happens now in Wikipedia, just throwing it in for completeness.
- Symbols for units of measure should never be italicized, and your use of italics is unclosed. Gene Nygaard 13:34, 20 Jun 2005 (UTC)
- I think we can assume US gallons for any contemporary context and only disambiguate the other cases. Actually it is just yet another reason not to use English measures at all. Christoph Päper 14:24, 20 Jun 2005 (UTC)
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- I've heard that many of the British still use miles per imperial gallon, though they buy their petrol by the litre. Their odometers are still in miles, anyway, so litres per hundred kilometres isn't any easier to calculate. It's even weirder in Canada, where I know many people who buy their gasoline by the litre and whose odometers are in kilometres still figure miles per imperial gallon. Gene Nygaard 05:16, 21 Jun 2005 (UTC)
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- The imperial gallon is still used when 'mpg' is quoted in Britain. As far as I know it is the dominant unit that British people use when discussing fuel efficiency even though fuel is sold in litres, not gallons. Manufacturers still quote it, for example Ford UK says the Focus does 8.7 L/100 km (32.5 mpg). Furthermore, in-car fuel efficiency displays quote 'mpg' and mean the imperial gallon. Many British readers assume that 'mpg' refers to the imperial gallon because they are not aware of any other gallon. I suspect that the same would apply in other countries. Bobblewik (talk) 10:40, 21 Jun 2005 (UTC)
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[edit] Proposed WikiProject
Right now the content related to the various articles relating to measurement seems to be rather indifferently handled. This is not good, because at least 45 or so are of a great deal of importance to Wikipedia, and are even regarded as Vital articles. On that basis, I am proposing a new project at Wikipedia:WikiProject Council/Proposals#Measurement to work with these articles, and the others that relate to the concepts of measurement. Any and all input in the proposed project, including indications of willingness to contribute to its work, would be greatly appreciated. Thank you for your attention. John Carter 21:04, 2 May 2007 (UTC)
[edit] Cleanup
I'm trying to clean up this article. I don't like having bullet points in the lead section but it's difficult to avoid here. Can anyone suggest a better layout? Biscuittin (talk) 22:47, 26 February 2008 (UTC)
- OK, done it. Biscuittin (talk) 09:06, 27 February 2008 (UTC)
[edit] Gallons Used as measurement for fuel in Burma
I'd like to see some references that support that Burma actually uses gallons as a measurement for fuel. The two links provided now are:
- 500 Are Detained in Burmese Capital "... the Government cut the ration of subsidized gasoline from six to four imperial gallons a week"
- Burma's Activists March against Fuel Price "The government, which holds a monopoly on fuel sales and subsidizes them, raised prices of fuel from 1,500 kyats (US $1.16) to 3,000 kyats ($2.33) per imperial gallon for diesel and to 2,500 kyats ($1.94) for gasoline."
These only indicate that gallons are used by the reporters that were writing about the events in Burma. The articles do not even touch the subject of what units are used in Burma. The second article even states the amounts in both US customary and SI units: "A canister of natural gas containing 65 liters (17 gallons) was raised from 500 kyats (39 US cents) to 2,500 kyats ($1.94)." The article also mentions US dollars. I hope you agree that these articles don't show that the USD is used in Burma as currency. Ulf Abrahamsson (talk) 18:15, 19 March 2008 (UTC)
[edit] Countries where this system is till in use
As far as I know, the only two countries that still use this form of measurement are the United States of America, and the United Kingdom, and they don't agree on what a gallon is. Is there any evidence supporting any other countries where this measurement is still officially used? (older generations in Canada talk of gallons, but in general no one really understands it when their elders talk crazy like that) --63.243.173.126 (talk) 10:58, 26 May 2008 (UTC)
[edit] Nautical mile
It is peripheral to this page, but it may be worth noting that despite the provisions of the UK's Units of Measurement Regulations 1995, the International definition of a Nautical Mile is 1852m, and most UK legislation in which it is relevant includes this definition (such as in "The Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations 1996, where it says "(3) In these Regulations... ... "mile" means a nautical mile of 1,852 metres") 82.152.253.130 (talk) 09:51, 2 June 2008 (UTC)
[edit] Common usage of gallon/litre etc
In the UK, it is no longer true to say that "Milk is sold in pints in all major supermarkets": it depends on the supermarket and on the dairy: Sainsbury's, for instance, sell their own label fresh milk in multiples of 568ml, but their own label UHT milk and most branded milk in litres. (see www.sainsburys.com)
And whilst there has been resistance to the change to metric units, it is dying out, and it is now rare to see the price of fuel "per gallon" quoted by anyone other than those who are trying to make a political point.
The idea that "Many British readers assume that 'mpg' refers to the imperial gallon because they are not aware of any other gallon." is interesting, but given that 95% of the world is not the USA, perhaps it would be more generic to say "Many American readers assume that 'mpg' refers to the US gallon because they are not aware of any other gallon." 82.152.253.130 (talk) 09:51, 2 June 2008 (UTC)
