
What's a Gallon? - billpg
http://grr.crankybill.com/2019/02/whats-a-gallon.html
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edw
Aside from the occasional crashed Mars lander, technical people in the U.S.
get along quite fine thinking in the units best suited to the task at hand. I
develop film in my apartment, and I use metric units while developing black
and white but conventional units while developing color slide film — because
the processes are documented in those respective units.

I don't know what kind of car Cranky Bill is driving, but if it's new enough,
chances are he could crack the manual and figure out how to switch it to
display values in liters/100km. My motorcycle does that, and my last car did
it. I set my motorcycle to display temperatures Celsius, speeds in whatever
the local country's unit happens to be, and fuel efficiency in mph.

Also, he might just look up the stats for his car on the Internet.

Bill sure is cranky.

~~~
billpg
I asked the people at Nissan and I was told it wasn't possible to switch it to
miles-per-litre. Although I do suspect the person I spoke to had no idea what
I was going on about.

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saltedshiv
But could you change it to km-per-litre?

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bonoboTP
Litre-per-100km is the European standard.

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tzs
Dimensionally, that has units of area, and so could be expressed in hectares.
My car is getting about 11.5 pico hectares.

~~~
bonoboTP
The same way that torque has the dimensionality of energy and can be measured
in joules.

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gambiting
I live in the UK and have my car set to litres per 100km - it's so much
easier, if I know my car uses 5L of fuel per 100km travelled and I need to
drive 300 miles(500km) down to London I instantly know that I'll need about 25
litres of fuel to complete the journey. Knowing that petrol is about
£1.30/litre also gives me an instant estimate of the cost of such journey.

The same thing with MPG: 5L/100km is about 56mpg, so for the same trip to
London we'll need about 5.5 gallons. Which is great to know except that I have
no idea how much is a gallon from the top of my head. I have to Google it,
apparently it's about 3.7 litres? But....that's not right, the figure is now
different. Ah. US vs UK Gallon, and of course Google shows me US Gallon as a
result for gallon, despite knowing I'm in UK. Imperial gallon is 4.5L and now
we arrive at the same number of 25L for the trip.

It's not impossible, I just find the first way much easier to work with.

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Aperocky
It's easier if the pump sells in liters, which is not true in the US.

You have 20 gallons, and 20MPG gets you 400 miles, that is an easy
calculation. All you have to do is to throw away all the metric unit.

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jfk13
20MPG?! You must be driving an American car. ;)

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colechristensen
I drove my parents farm truck for a couple of weeks to commute because my car
had broken down and boy was that expensive. 12 mpg if I remember correctly.
The gas pump at the station would stop at $100 and the tank wouldn't be full.

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Aperocky
LOL, it sounds like you're driving a semi to work.

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9nGQluzmnq3M
Serious question: why hasn't the UK switched to km yet? Everything else is
metric/decimal now, it seems really weird to get stuck on this one last relic.

~~~
billpg
I still meet people who argue that pre-decimal currency was better. (20
shillings in a pound. 12 pence in a shilling.)

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johannes1234321
12 ist a fantastic number for doing maths in your head. 12 divides easily by
1, 2, 3, 4 and 6.

~~~
9nGQluzmnq3M
Have you considered joining the Dozenal Society?

[http://www.dozenal.org/](http://www.dozenal.org/)

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mabbo
I think the more important difference than miles or km is which is the
denominator and which is the numerator. The rest is just some multiplication
factors.

As another poster pointed out, using [fuel]/[distance] (like l/100km) means I
can easily estimate how much gas I need given my decision on where I'm going.
Using [distance]/[fuel] (like miles per gallon) is only useful in a situation
where I've filled my tank up and ask "Now where could I get to with all this
fuel?". I don't think that happens very often.

I suppose it might also be useful in a situation where you're low on fuel and
asking "oh Jesus, can I make it to a gas station?", but most cars now have a
"[distance] to empty" display on the dash anyway.

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oldandtired
Here in Australia, we still talk about 44 gallon drums, which are equivalent
to the 55 gallon drums of the USA variety. Both Miles per Gallon and Litres
per 100 Kilometres are still used in various ways.

The gallon is approximated by 4.5 litres and the mile is approximated by 1600
metres as simple conversion factors. Often we use both centimetres and
feet/inches for peoples height.

Over the years, there have been various discussion amongst friends as to why
Americans have this penchant for speaking in feet, pounds and gallons?
Sometimes, it has been concluded that Americans like big numbers, so the use
pounds instead of tons (or tonnes), etc. We have discussed, at times, why
Americans used a smaller grouping system that increased by factors of 1,000
instead of 1,000,000 when using billions, trillions, etc. So you get the
discrepancy at times of trying to determine whether someone who is using
billion is talking about 1 million million or 1 thousand million.

Much as metric can be difficult to get used to with its basic sizes, it is at
least consistent in being based on the count of 10 and having a common set of
prefixes for size changes.

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billpg
No but seriously, what _is_ a gallon?

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sverige
I learned this when I was about five years old:

A cup is 8 ounces. Two cups in a pint, two pints in a quart, four quarts in a
gallon. In other words, 128 ounces. This is of course for U.S. gallons.

A lot of things now measured in the metric system are still based on the
standard U.S. system, just converted to metric. This is, for example, why
whisky comes in 750 ml bottles instead of (say) one liter bottles. It was
traditionally sold in fifths (of gallons); i.e., 25.6 ounces, which converts
to 757.1 ml. It's also why there are track events of 100 meters, 200m, 400m,
800m, and 1600m. They are near the distance of the old races, and it seems
especially noticeable to me for the half mile and mile, probably because I ran
those races when I was a teenager.

Thankfully there's almost zero chance the U.S. will convert to metric in my
lifetime. I can feel miles and gallons and Fahrenheit in my bones. Metric, not
so much.

~~~
dreamcompiler
Or if you're a binary geek like me, 1 gallon = 2^7 ounces.

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simonblack
An obsolete measurement of volume.

Only a few countries are too immersed in their self-centred past to use the
world-wide metric system.

That refusal to progress has cost millions (billions?) when different units
have been used without conversion.

[http://edition.cnn.com/TECH/space/9909/30/mars.metric.02/](http://edition.cnn.com/TECH/space/9909/30/mars.metric.02/)

~~~
knob
Always remember: There are two types of countries in the world.

Those that use the metric system ...

And those that have gone to the Moon.

~~~
shirro
There are only two types of countries in the world. Those that lost the
ability to launch people into space and those that adopted SI units.

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jkingsbery
The Imperial system of units is useful in lots of scenarios, and it's worth
giving a try. You shouldn't judge a person's choice of units until you've
walked 1.6 kms in their shoes.

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Jun8
It’s interesting that the widely used units gallon and barrel (as in oil
measurement) are both of uncertain etymological origin.

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twothamendment
Almost more interesting that the article - this is the third time it has been
submitted. The first two died at 2 and 1 points, but while I write, the third
is at 17 points. I guess the third time is the charm.

What was different with this submission? Time of day? The other stores that
were new at the same time?

