>>In Canada we also "officially" use litres/100km, which is one of those counterintuitive measures only scientists love.
>
>Intuition is a habit.

True in this case. I just tried thinking in gallons/100miles but that needs too many decimal places for the average punter to comprehend :-}

Maybe gallons/1000miles would work - but then you would find people who had to drive 1000miles before they could work it out.

>
>Here, a common car talk goes like "how much does it consume", "good, below six now, but until my guy fixed it it was devouring over eight comma six". The "per 100 km" is assumed without mention.