In the USA, gas is sold by the gallon while it’s sold by the liter overseas and in Canada (the latter according to my Canadian friend from PEI). Is this because there isn’t a metric equivalent of the imperial gallon? Is it a sales scheme where $1.75 a liter looks a whole lot better than $7.00 for 4 liters? Or are cars much more fuel efficient that the cars fill up faster than cars in the USA?
Well, a litre is the metric equivalent of the gallon, in the sense that stuff measured in gallons in the US is measured in ltres everywhere else. So it’s the metric equivalent of the quart, too.
But what else would you expect petrol to be measured in? Would you think it sensible to buy petrol by the millilitre (or cc)? Or by the kilolitre (or cubic metre)? There isn’t any other metric unit available in this size range.
The liter is the metric equivalent to the gallon. That is to say, it’s the standard unit for measuring volume.
Well, I suppose we could use the decalitre, but if you think folks are confused about the metric system now…
Besides, you get used to it. Now a gallon seems like a big clumsy unit to measure a gas tank content. Smaller units give you more precision without having to use decimals, (immagine if American pumps used strict imperial units, and gas was measured in gallons, pints, and ounces) Besides, the litre isn’t so small that the numbers get unweildly. Tanks on both our cars are about 60 litres. A minivan I rented once seemed to have about a 100 litre tank.
You’re overlooking the importance of tradition. Selling gas by the gallon is a long-entrenched custom in the U.S., and there’s no compelling reason to change it. On the other hand, Canada embraced the metric system and uses it extensively. No one made a decision based on the actual size of the common units (e.g., gallon vs. liter). They just use the units available in the system they’re accustomed to.
I just can’t imagine Americans using the imperial gallon for gasoline.
Why not? Buy 4 quarts, get 1 free! I would go for it…
“Sold by the litre” doesn’t mean you have to buy the same number of litres as you would buy gallons in the USA 
I live in the UK, and gas (or petrol, as we like to call it) was sold by the gallon until about… ooh, probably 15 years ago, maybe 20. (I’m 29, and I certainly remember it switching over to metric). We used imperial gallons (which are not the same as US gallons, incidentally), and it just meant that instead of buying 10 gallons at £2.09 a gallon, you’d buy 45 litres at £0.46 a litre. (Although nowadays you can double those prices, of course 
)
The bottom line is, whether your buying it in litres, gallons or thimblefulls, you’re paying a lot less for it than we are…
A bit of Googling suggests that UK filling stations switched over in about 1990, so I was about right with that guess.
This is what I don’t understand in the OP though:
Why on earth would they quote a price per 4 litres? You might as well ask why US filling stations don’t quote the price per quarter gallon. The litre is the basic unit, so it makes sense to quote the price per 1 unit.
I remember seeing gasoline sold by the liter in the USA when the price exceeded 99 cents per gallon. The old gas pumps couldn’t handle three digit prices. It didn’t last too long.
I always thought that a liter was roughly equivalent to a quart. A gallon is four quarts. Hence my statement. I know there isn’t a metric unit close to a gallon.
The museum is currently stuck in the mud. Oops.
Don’t you hate it when you reply to the wrong thread? :smack:
Worse, the Canadians used to use the imperial gallon, and we use the US gallon. Most of the non-imported Canadians still talk in gallons, but we (Americans) have to understand that we’re not talking the same language. Also here the official fuel efficiency measurements are in L/100km, but most of the Canadians still talk about MPG, but imperial miles per gallon. When we absolutely must be clear with each other, we just revert to liters – or, as they would spell it, litres.
FWIW, Canada’s metric by statute, not by common use. In the grocery stores the produce is always sold in pounds (if not by unit). The meat is always priced in units of 100 grams, though, but I always ask for it by the pound (the one time I asked for a half-kg, the poor little [young] clerk didn’t even know what the heck I wanted). Milk is mostly “four litres” but the convenience stores have single, US (not Canadian) gallons (cross-labeled in liters, of course).
Here in British Columbia the grocery stores sell their produce by the kilogram if you read the receipt. Produce is labelled by by both kilogram and pound.
Processed meats (deli) are, but fresh cuts are mostly sold by the kilogram.
I’ve never seen that on the west coast. Does 7-11 in Burlington,Ontario get their milk from Buffalo ?
And here we spell liters both ways.
I only see produce in the store labeled by the pound, and have never looked at the receipt. I never see advertisements outside the store (e.g., newspapers or whatever), so I can’t attest to their advertising. I’ll be sure to check my receipt next time, though, although that seems like it would be deceptive, no? Selling it on the shelf for one price and thoroughly confusing you when looking at the receipt?
Oops… meant to be more distinct, so I will. It seems that everything in the deli is sold per 100 grams; meats from the meat section are in kg. At the deli, too, now that you remind me, I’ve asked for quarts of things (salads, whatnot) and haven’t had problems. Of course I’m always charged by the gram, but really – I don’t know what 200 grams of potato salad weighs – I want a quart!
I don’t know – I thought there was a large dairy industry in Ontario. I tell you, though, that it was a blessing to find those 1 gallon jugs at the 7-Eleven because I couldn’t figure out for the life of me how to manage those damnable four liter bags when all the supermakets had were tiny, little liter-sized milk pitchers. (For you other Murkins, it turns out the 4 liter bags contain 3 each 3-1/3 liter bags, which fit quite nicely in said little, liter-sized milk pitchers.)
And here we spell liters both ways.
[/QUOTE]
And I admit to sometimes spelling labelled both ways. 
Ew. I’ll stick to cow’s milk, thanks.
In Britain we buy petrol by the litre, but measure fuel consumption in miles per gallon, the older measure having stuck because we still measure distances and speeds in miles and mph. Miles per litre or litres per 100 miles just sound wrong.
Although all car adverts now quote the “litres per 100km” figure as well as mpg. And, of course, CO[sub]2[/sub] emissions are given in g per km.
There are mutterings about converting all UK road signs to show kilometres instead of miles, but I can’t see it happening for a while. Apart from anything else, it would be a great shame to lose the traditional old fingerposts and replace them all with ugly modern signs.
It may surprise the OP to know that other countries also measure distance in meters and kilometers, weight in grams and kilograms, and temperature in degrees celsius.
I don’t even understand the point of the OP, or why petrol/gas in particular is being singled out for attention. Countries measure using the units that have become standard in those places. Perhaps the argument is that everyone else should use the same units as the US, so Americans won’t get confused when they travel.