Units in Europe for fuel

[Prpn 366]

Love how this turned into a generic imperial vs. metric topic, haha. My favorite view on this comes from some book, I don't know the source, just found the image online once and kept it around. One curse word in there, so I won't post it as an image here, just a link: https://i.postimg.cc/xC0h9F27/20180713-120111255-i-OS.jpg

Otherwise, it really is just what you are used to or grow up with. For that matter, I don't know anyone who goes and orders cheese or meat by decagrams... you order 300 grams, or half a kilo, or 700 grams etc 🤣.

Against arguments that imperial is more 'natural', I counter this:

Imperial is “natural”

This myth is commonly stated in the British media and presumably only refers to the foot. What part of the body is a pound? What naturally corresponds to a pint?

However, a little thought shows that this is an empty justification for using imperial. A unit needs to have a standard size otherwise there would be complete chaos. Human feet are not a standard size and so there is no natural size for the unit. The fact that human feet vary led to many different standard feet in Europe in the past.

In fact very few people have feet that are as large as the imperial foot. You would need a British size 12 ½ foot! The vast majority of people have smaller feet. The average human foot is 24 cm versus 30.48 cm for the imperial foot.

If an imperial foot is “natural” then by implication most people have unnaturally small feet! If in doubt try measuring your own feet.

Source: https://ukma.org.uk/why-metric/myths/imperial/ (possibly slightly biased, but the facts seem to check out).

[SAS443 1,723]

Just refuelling my C172S is an exercise of cerebral fitness.

• Measure fuel rem. in each tank with a measuring stick which has a marked index (inches?) on it.
• find the corresponding gallons on a conversion table inside the plane
• adjust fuel remaining in the G1000 menu
• If you need to refuel, skip the step above, instead:
  • refuel the plane, but quantity is measured in liters at the pump
  • update fuel rem in Efis, but don't forget to convert uplifted fuel into gallons or use the measuring stick.
  • adjust W&B, convert fuel onboard (weither it is Gallons or liters) to weight (kilograms)
  • Or just fill her up and make it easy on yourself. 😁

Edited May 24, 2022 by SAS443

[Ray Proudfoot 8,957]

Sixty years ago the French and British formed two teams to design Concorde. The French worked in metric, the British in imperial.

They also had a language barrier to overcome. It didn’t prevent them building a magnificent aircraft. And they didn’t have calculators, just slide rules and a desire to succeed. 😉

With my long term interest in the weather I can instantly convert any temp in Fahrenheit from 0°F to 100°F to Celsius in my head. Vice versa too. Rainfall in mm to inches just divide by 25.

The only one that I cannot cope with is wind speed in metres per second. ☹️

I’m an old git which might explain why I can cope with both systems. 😁

[keithb77 308]

Imperial IS more natural as it's based on dividing/multiplying by halves (or multiples of halves) which everyone can do in their head, decimal is a bodge - you have to multiply by two, save the result, multiply again by two twice and add the saved result ... I remember writing code in Z80 assembler to do just that way back when.

I think the first foot was a King's and of course he was bigger than all of his subjects (or wanted them to think so) so we had the original BigFoot 🙂

[neucoas 82]

People. Multiple and divide by 10 is as easy as moving the decimal point on the number  

[Prpn 366]

19 minutes ago, keithb77 said:

Imperial IS more natural as it's based on dividing/multiplying by halves (or multiples of halves) which everyone can do in their head, decimal is a bodge - you have to multiply by two, save the result, multiply again by two twice and add the saved result ... I remember writing code in Z80 assembler to do just that way back when.

It is really, really subjective. I'm not sure what you are trying to do that requires the steps you describe, but the simple fact that imperial units have no easy way that relates them just makes them quite hard to use if you don't grow up with them. Individual units, sure. Like if you only ever deal with mph, or feet etc. But if you need to know one relative to the other, it is just a mess. One mile is 5280ft, which is 1760 yards, or 320 rods, where a rod is 5,5 yard?

Is it harder to divide or multiply by tens or thousands (literally adding a zero or moving a decimal point) then trying to multiply 1760 by 3 in your head? Growing up with metric, I want to logically say no. But I did not grow up with imperial, where that might be ingrained into your brain and life. I can work with pretty much anything, I mean, even m/s wind is an easy conversion to kts for example, which is then mostly used in aviation. But I think objectively speaking, a system that does not use arbitrary old school references for units, but systematic and easily relatable units should have the upper hand. Which is kind of what you see in what system is used where throughout the world and in most scientific circles.

Edited May 24, 2022 by Prpn

[neucoas 82]

And let’s not get started discussing how US people write cooking recipes with cups/tablespoon/whatever lol

[SAS443 1,723]

1 hour ago, Ray Proudfoot said:

The only one that I cannot cope with is wind speed in metres per second

It's rather straightforward 🙂

M/S is roughly half the windspeed in knots

2 m/s = 4kts
4 m/s = 8kts

etc.

[Ray Proudfoot 8,957]

Just now, SAS443 said:

It's rather straightforward 🙂

M/S is roughly half the windspeed in knots

2 m/s = 4kts
4 m/s = 8kts

etc.

Thanks! I still prefer mph for wind. Easy to understand when speed limits on our roads are in mph.

[Prpn 366]

50 minutes ago, Ray Proudfoot said:

Thanks! I still prefer mph for wind. Easy to understand when speed limits on our roads are in mph.

So add 15% on top after multiplying by 2 😛. Or, for easier calculations and for the most common wind speeds, you could just easily add 10% and you won't be off by much more than 1-3mph up to about 60-65mph winds. Fun stuff 😁.

[Ray Proudfoot 8,957]

4 hours ago, Prpn said:

So add 15% on top after multiplying by 2 😛. Or, for easier calculations and for the most common wind speeds, you could just easily add 10% and you won't be off by much more than 1-3mph up to about 60-65mph winds. Fun stuff 😁.

😁 that’s too much effort, sorry. My weather station (link below) shows wind in mph. Nice and simple. 😉