A retired sheep farmer friend of mine was talking about petrol prices today and how we in NZ pay more than 'those Americans'. I said, but they're paying over $4 a gallon. He proceeded to tell me there were 4 litres to the gallon - to which I said no, quarts are bigger than litres and there are 4 quarts to the gallon. Then he said that of course the Imperial gallon was bigger than the American gallon because the Americans could get 50 gallons into a 44 Imperial gallon drum. We haggled a bit more and I threw in that there were 64 ounces to a gallon which made him think and bought me time.
When I got home, I Googled these things and found that he is right. There are 3.785 litres to the American gallon which means that with the present price of $2.089/litre of 91 petrol, New Zealanders pay $7.91/gallon or USD$6.24/gallon. So in fact, we do pay more for regular petrol than 'those Americans'.
The moral of the story: don't argue with retired sheep farmers - and go light at the petrol pump.