Energy per distance, better than gallons/liters?

[Autobahnschleicher]

Unlike barleycorns per tablespoon or whatever, Wh or Joules per km makes sense, is easy to use for range and emissions calculations and not based on an archaic system of people with unusualy large feet.
Alternatively use Joules per Meter or Kilojoules per Kilometer if you want smaller numbers.

But the metricly impaired will cry a river about the metric system beeing "less intuitive" because they didn't grew up with it.

[Piotrsko]

I remember the same noise when the UK changed their pound to 100 pence, but they actually have backbones.