For example, while we in the UK we still habitually use imperial measures to weigh ourselves rather than metric, we don't know our weight in pounds, but in stones and pounds, which gives a more manageable/comparable number.

It's so habitual to do that, that many people (including me) can't easily do the mental maths conversion to a US-style imperial weight at all.

It still enrages me that there are 14 pounds in a stone but 16 ounces in a pound. What kind of system of logic is that?

At say 30mpg (city driving) isn't that 37p per mile?

Unless you're prepared to write off the share of running costs, MOT, tires, insurance which costs a fortune, and is all intended to be covered by the 45p per mile, is it not? All of which could rise by 8% this year (inflation prediction).

As far as I remember reading, most people would already be subsidising once the fuel part reaches about 28-30p per mile.

From what I can tell, very few people in the UK have done the maths as to what is coming for cost of living in the next few months. If the government does not do more than the pathetic measures they have already announced, there will be riots. It is going to be bad on a scale that a person of the median age is too young to remember.

For example, 7 litres / 100km = 0.07 mm^2

It's the cross-section of a noodle of fuel laid out along the road that the car needs without a gas tank.