I am British and when I buy petrol I'm generally conscious of the amount. Can't guage it very precisely because of the flow rate at the pumps. I might tank up now and then if I'm going on a long journey, but this putting 'ten quids worth' in doesn't seem sensible to me, it doesn't mean a thing. After all if you are refueling you wan't to make sure you've enough to be going on with, unless you find stopping at filling stations geat fun. The rate of consumption of my car tends to remain the same but the amount you get for 'ten quid' doesn't.
I don't know how typical that is but I doubt I'm that rare in my thinking. Buying by cash was probably more common back in the days before plastic when people were trying to run a car on what they had in their wallet at the time.
A good point about cash versus cards.
I always fill 'er up and pay by credit card.
However my more frugal other-half has put round cash in before (despite not realising there's no difference in the long run).
I would "put 5 quid in" if I was selling a car and the tank was near empty
I suspect those without credit cards may put in round cash amounts - I don't know if you've noticed but many petrrol stations have "penny saucers" where you're allowed to take a penny of two if you "dribble over" the round amount.
