Thread: MPG vs L/100k

Who remembers when fuel was sold by the gallon, in square cans, and we had to know how far we were traveling, to know how much fuel to buy?
Who remembers the old hand pumped fuel bowser's, I do.

As far as I can see, the only reason we have this ridiculous Ltr's\100 Km's, is some public servant reckoned it didn't sound right.
Being a long distance traveler, I have always calculated fuel consumption in either gallons\litre's per hour, or tons\tonnes per day.

And just where the hell does a 50% fuel efficiency increase come into your fantasies? Damned good engine tuner, and I want him to do mine right now.

Did someone say pedantic's?


BigJon.
Your Dad is not the only one like that mate. We have to suffer a 10 times less accurate national measurement system because some silly public servant females of the opposite sex, don't want a set of massive 900 mm boobies.
90 cm is much neater to their mind.
I like em best at 36" myself.

Hey Strangy, how does 96 ton per day sound? Economical running that is, get much "better" fuel burns at higher speeds.
50,000 HP uses a LOT of fuel.

Originally Posted by Bushie

The real problem lies with the 'imperial' system.

Mile - Nautical or Statute

A nautical mile makes sense when you understand the reasoning behind it:

Without regard for global position, an arc equal to one minute of difference in latitude measurement is approximately 1 nautical mile. This gives 1 nautical mile per for every minute (1') of change in latitude. This is one advantage in measuring latitude with respect to angles originating at the center of the Earth.

• Conversion Notes
• 1 nautical mile = 6076 feet or 1852 meters
• compared to 1 statute (land) mile = 5280 feet or 1609 meters
• 1 nautical mile = 1.15 statute mile
• 1 knot = 1 nautical mile per hour

Using the mathematical technique of "units analysis", one can see the relationship between the earth's circumference and a nautical mile as the distance along one minute of arc lattitude by the following equation (1 Earth circumference)/(360 °) x (60')/1° x (1 nautical mile)/(minute ' of arc) x (1.15 statute miles)/(nautical mile) = 360 * 60 * 1.15 statute miles

= 24680 miles around the earth traveling through the poles

And the whole damned world should change to that system, because there is more water than land, so it is logical. Right?

Honestly, everyone replying to this thread must be at work to have so much time for their long answers!

Well, I am, anyway.

The use of different measurements is easy:

Human height: Imperial
Weight: Metric
Newborn baby weight: Always Imperial
Newborn baby size: Always Imperial
Speed of vehicle: Metric
Speed of vehicle at speedway: Imperial
Measuring things precisely: Metric (mm)
Measuring things roughly: Imperial (there're no inches in Metric)
Measuring precision engine parts: Imperial (so you can say things like " 3 thou")
Describing the weight of really big things: Tons or tonnes, it doesn't matter as everyone just says "tunns"
Fuel capacity: "F" or "E"
Mileage: It doesn't matter as it's always better than the guy you're talking to

Actually, I used to use Imperial for fuel calculation and then changed to l/100km when I moved up here, because everything is so far away it's always hundreds of k's anyway.

Originally Posted by BigJon

Perhaps that stems from two things,

1: Growing up they would have had their height measured by their parents, possibly using the imperial system.

2: Having to explain to old people who only 'understood' imperial measurements what their height in cm actually meant.
Incidentally, my Dad (an engineer of some repute) always used to drill mm into me, saying cm are for dress making .

Too true. AFAIK cm are only used in haberdashery.

We measured our children's heights as they grew up, and did it in mm's, as that is what they were going to learn in.

Funnily enough, decimal currency (metric) was introduced (1966) when I was still at school, whereas measurement ie mm's, klm's etc, didn't change until 1976, and I had finished my trade 6 years previously, and had to get used to a new form of measure. Not easy to do when you're indoctrinated with something else.

Originally Posted by p38arover

A nautical mile makes sense when you understand the reasoning behind it:
[/indent]

1 knot = 1 nautical mile per hour.


It always amuses me when people say something like they were doing "45 knots per hour". My response is the acceleration must have been pretty good, what was the top speed?. I usually only get a blank look in return .

Originally Posted by BigJon

1 knot = 1 nautical mile per hour.


It always amuses me when people say something like they were doing "45 knots per hour". My response is the acceleration must have been pretty good, what was the top speed?. I usually only get a blank look in return .

Lousy acceleration factor that one. Only a 45 knot increase every hour?
Of course that still puts it at USS Enterprise's top speed in about 1 1\4 hours.
From stand still.

That's rated by "Janes", as 55+ knots.

It should only take about 7 or 8 days to leave orbit.

Originally Posted by BigJon

1 knot = 1 nautical mile per hour.


It always amuses me when people say something like they were doing "45 knots per hour". My response is the acceleration must have been pretty good, what was the top speed?. I usually only get a blank look in return .

Haha yeah, I heard someone say that at an aircraft museum. Tour guide went ape sh.t

But I need acceleration in metric to understand the "joke"....

45 knots per hour
= 45 nautical miles per hour squared (per hour per hour)
= 83,340 metres per hr^2
= 23.15 m/s^2. (Did I get this right)