Within weeks those metric symbols disappeared as people would only buy gas at stations that had retained the Imperial measurements.

Very admirable behaviour on the part of the American public - though I'd put it down to righteous bloody-mindedness rather than "People were confused and couldn't figure out how much per gallon they were actually paying", which would suggest that American drivers are stupider than English drivers who adjusted to the new pumps without much of a fuss.

But American gallons are not "Imperial measurements". Both sorts of gallons are eight pints, but an American pint is 16 fluid ounces, and an Imperial pint is 20 ounces.