America is still mainly Imperial measurements, but they mainly quote a persons weight in pounds and
their mile is shorter than the British mile and I'm pretty sure that their gallon is a bit less and as for engine capacity in cubic inches which I'm pretty sure never was used in Britain (We've always quoted in cc or litres)
its all rather confusing really to quote Spike Milligan.
I remember in my local when they said beer would soon be sold in half litres I commented that we had been served half litres for years and was ridiculed so next time I went in I had a 500ml bottle of beer with me, made sure I had an audience at the bar and asked for a pint glass into which I poured the bottle. Lo and behold a pint with a head.

It led to some muttering and people asking the landlord to "Top that pint up" for quite a while.