Metric Fuel Consumption

[Vanin]

PenelopaPitstop said:

Miles per gallon are useless to me. I don't buy petrol by gallon and my tank size is quoted in litres as well. I only learned some estimated conversions between l/100km and mpg to quote it to British. Otherwise I think in km and in l/100km. It all depends where you come from and what is standard for you.

When I check car spec and it says 80l tank, I can easily count how many km I can do on the tank and only then convert km to miles.

Can you not read? I did not mention gallons in that quote. What I queried was why the Europeans had gone for litres/100km instead of km/litre

[kambites]

Everyone who uses angles for anything serious uses radians.

[Vanin]

And still nobody has come back to me about why the French, the instigators of the metric system, still sell their national product wine by the case which is a dozen bottles (a dozen is twelve by the way for all you younger metricgeeks)

[kambites]

Because 12 is 3x4 which makes a conveniently shaped box?

[thegreenhell]

The only reason that the decimal system is so prevalent is because most of us have 10 fingers, which makes for easy counting. If only we had an extra digit on each hand then we'd all be using the duodecimal system, and most of these odd units would make much more sense. 12, and multiples thereof, is much more readily divisible into useful fractions than 10, so using base-12 as our counting system would make life a lot easier.

[kambites]

Indeed, but given that we do generally count in base-ten, decimal units make life considerably easier.

[saaby93]

thegreenhell said:

The only reason that the decimal system is so prevalent is because most of us have 10 fingers, which makes for easy counting. If only we had an extra digit on each hand then we'd all be using the duodecimal system, and most of these odd units would make much more sense. 12, and multiples thereof, is much more readily divisible into useful fractions than 10, so using base-12 as our counting system would make life a lot easier.

Even during the times most people had 10 fingers it was still more common to have dozens for useful things which to some may have been gross.
Surely today 16 is the most used counting system even if it is largely hidden

[kambites]

saaby93 said:

Surely today 16 is the most used counting system even if it is largely hidden

Or two, depending on how you look at it.

[RBH58]

LimaDelta said:

Try general aviation in the UK...

Altitude - ft
Distance - nm
Runway length - m
Speed - Kts
Fuel - lbs
Fuel flow - GpH
Air pressure - Hpa (mb)
Manifold pressure - inHG
Power - hp
Engine oil - quarts
Air temp - DegC
Oil temp - DegF
Oil pressure - PSI

And probably others I've forgotten to mention.

For an industry that relies so heavily on “standards” and the adherence to them for safety, this is actually quite alarming. Any confusion can (and HAS!!!) led to people getting killed.

[Horsetan]

saaby93 said:

snt it because they thought there were about 360 days in a year
To change that to metric you'd need to do something significant

...like the 1789 French Revolution, which really did impose ten-day weeks, each day split into ten hours of 100 minutes each.... They still kept to twelve months in a year, though....

[mondeomk4]

It is a good point that the distance is in miles and the fuel in litres, it might be useful to think of miles per litre when getting fuel.
As there are about 4.5 litres per gallon, divide the mpg by 4.5 (or by 5 for simplicity) to get an approximate MILES PER LITRE which is the mixed system measurement we use.

Eg it you do 30 mpg it is 6 and a bit miles for the £1.20 litre you bought.
If you do 45 mpg it is 10 miles for the litre of fuel.

Edited by mondeomk4 on Thursday 23 November 23:20

Edited by mondeomk4 on Thursday 23 November 23:26

[donkmeister]

I'm all for distance/volume whether it be mpg or km/l (the latter is used in Oz i understand).

Regardless of whether you are for distance/volume or volume/distance L/100km doesn't work as a unit. L/km or l/1000km would not upset me as they are metres to the third and sixth power of 10 and therefore proper in the metric system... but a hecto-kilometre?!
Raise a unit to the 5th power? bks. Do you inflate your tyres to Pascals of pressure? Nope. 5th power again. Stupid idea.

[Mr Tidy]

Horsetan said:

Or possibly miles per litre. That should work too.

That's what I use, even thought my cars record economy on the OBC in mpg! (Can always multiply by 4.54whatever....).

[RBH58]

donkmeister said:

I'm all for distance/volume whether it be mpg or km/l (the latter is used in Oz i understand).

Regardless of whether you are for distance/volume or volume/distance L/100km doesn't work as a unit. L/km or l/1000km would not upset me as they are metres to the third and sixth power of 10 and therefore proper in the metric system... but a hecto-kilometre?!
Raise a unit to the 5th power? bks. Do you inflate your tyres to Pascals of pressure? Nope. 5th power again. Stupid idea.

Aus uses L/100km

[Toltec]

I don't know about the rest of you but I just use the remaining range readout to work out when I need to fill up or reset the trip and use that in an older car.

mpg, km/l, cl/km can be used in whatever way works for the task at hand.

About time we ditched speedometers and had a chronometer that reads seconds per km or hours per 100km so it is easy to tell how long it will take to get somewhere.

I can do the Keithley run in 12 kilosecs etc.

[Gojira]

Toltec said:

I can do the Keithley run in 12 kilosecs

[GravelBen]

kambites said:

Everyone who uses angles for anything serious uses radians.

Except for surveyors, we use degrees/minutes/seconds (and also get a lot of practice at converting various ancient distance and area measurements to metric... links, chains, acres, perches etc).

ETA: 1 second of arc is 0.0000048 radians, so using D/M/S instead saves a lot of extra zeros.

Edited by GravelBen on Friday 24th November 06:34

[GravelBen]

Mr2Mike said:

Litres/100km is intrinsically stupid and clunky, where did 100km come from? That's not a standard unit of distance.

Its just easier to talk in x.x litres/100km instead of 0.0xx litres/km. Being sensible metric units its very easy to convert those, you just move the decimal point across instead of having a completely different number.

Mr2Mike said:

If we were currently measuring fuel use in something equally stupid like miles/10 pints you might have a point.

What, like gallons? You measure your fuel use in sets of 5280 feet per 8 pints which seems a little daft to me. (yes I had to look up both feet/mile and pints/gallon because they're out of date archaic units that mean nothing to me* and serve no purpose other than complicating things and making old people nostalgic).

*apart from pints of beer, I still drink those and don't complain about the silly measurement

Edited by GravelBen on Friday 24th November 06:36

[ajprice]

When there's a thread about a VW Lupo 3L and everyone thinks it's got a 3 litre engine

https://www.pistonheads.com/gassing/topic.asp?t=15...

CrutyRammers said:

normalbloke said:

This thread title had so much hope, the reality has shaken me to the core......

me too. How things have changed, when "3 litre car" now refers to fuel consumption.

[Crosswise]

Someone mentioned Canada earlier, and although it is definitely Km and Liters when it comes to driving, it is probably even more confused in many other regards. It is officially metric, however, as a lot of equipment comes from the US, it is far more common to use imperial. Today, in my job alone, we have set up 2 identical high pressure pumps, both control panels have the flow in gpm and pressure in psi, one has the motor temperature in Fahrenheit, one in centigrade. We've installed metric sized junction boxes in imperial housings using a combination of metric and imperial fixings. At least once a week I deal with the results of metric bolts being forced into imperial fittings or the other way round.

The UK is far from unique.