I believe that it is far more efficient to list fuel
efficiency in miles per gallon. Miles per
gallon is already widely used, and it would be very difficult and costly to
replace the labels from miles per gallon to gallon per mile. Sometimes when something is not broke it is
unnecessary to fix it.
It is far more effective for the average driver and consumer to think of their fuel consumption in regards to the amount of distance they can travel on that individual gallon, as opposed to the other way around. It has also been the standard for some time and could cause confusion, especially to older consumers, to change.