4 ms·

That really is a remarkable visualization! So much so that I had to compute it for myself - 27,000 liters of gasoline will move an average car 287,000 km assumi

That really is a remarkable visualization! So much so that I had to compute it for myself - 27,000 liters of gasoline will move an average car 287,000 km assuming 9.4L/100km which is the average 2017 fuel economy for a "car, light truck, SUV" in the US.[1] [1] https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles https://en.wikipedia.org/wiki/Fuel_economy_in_automobiles

userbinator 7y ago
Relatedly, fuel consumption can be measured in square meters: https://physics.stackexchange.com/questions/325733/why-can-fuel-economy-be-measured-in-square-meters https://physics.stackexchange.com/questions/325733/why-can-f...
- HALtheWise 7y ago
  Yes, and the grandparent's calculation can be accomplished by simply dividing the fuel volume by the "area" of the car's efficiency (or multiplying if using MPG, which is inverse area) https://www.wolframalpha.com/input/?i=%283m%29%5E3*24.9mpg https://www.wolframalpha.com/input/?i=%283m%29%5E3*24.9mpg
  - tzs 7y ago
    Pico hectares are a good unit of area to use for this. For a car that gets N miles/gallon, for 1/N gallons/mile, that works out to 235/N pico hectares. That results in nice small, but not too small, numbers for most current cars, around 50 pico hectares for a Humvee in the city to around 4 pico hectares for a Prius on the highway.
    - seszett 7y ago
      Square centimeters or millimeters seem easier to visualise. The area represents the size of the tube that feeds the engine to get this mileage. You could even express it in the form of a radius.
    - Svip 7y ago
      I cannot really find a standard definition of pico hectares, but am I correct in assuming we're talking about 0.01 mm²? Or 1 square hecto-micrometre, I guess.
deleted 7y ago
[deleted]
roel_v 7y ago
2 other numbers I read today on HN that made me look at things differently, although I knew them in other units but those didn't 'click' as much: air (including the water in it) weighs about 4 kg/m3 (much more than I would have intuited), and the whole US uses 'only' 1.3 km3 of water per day.

userbinator 7y ago

Relatedly, fuel consumption can be measured in square meters: https://physics.stackexchange.com/questions/325733/why-can-fuel-economy-be-measured-in-square-meters https://physics.stackexchange.com/questions/325733/why-can-f...

HALtheWise 7y ago
Yes, and the grandparent's calculation can be accomplished by simply dividing the fuel volume by the "area" of the car's efficiency (or multiplying if using MPG, which is inverse area) https://www.wolframalpha.com/input/?i=%283m%29%5E3*24.9mpg https://www.wolframalpha.com/input/?i=%283m%29%5E3*24.9mpg
- tzs 7y ago
  Pico hectares are a good unit of area to use for this. For a car that gets N miles/gallon, for 1/N gallons/mile, that works out to 235/N pico hectares. That results in nice small, but not too small, numbers for most current cars, around 50 pico hectares for a Humvee in the city to around 4 pico hectares for a Prius on the highway.
  - seszett 7y ago
    Square centimeters or millimeters seem easier to visualise. The area represents the size of the tube that feeds the engine to get this mileage. You could even express it in the form of a radius.
  - Svip 7y ago
    I cannot really find a standard definition of pico hectares, but am I correct in assuming we're talking about 0.01 mm²? Or 1 square hecto-micrometre, I guess.

deleted 7y ago

[deleted]

roel_v 7y ago

2 other numbers I read today on HN that made me look at things differently, although I knew them in other units but those didn't 'click' as much: air (including the water in it) weighs about 4 kg/m3 (much more than I would have intuited), and the whole US uses 'only' 1.3 km3 of water per day.