I don't know the whole story, but there is (or was?) an organization called the Gasoline Pump Manufacturers Association that dates back to at least the 1930s, w

I don't know the whole story, but there is (or was?) an organization called the Gasoline Pump Manufacturers Association that dates back to at least the 1930s, which seems to have some role in it. Also quite a bit of government involvement, since the measuring parts of the pump fall in the category of "weights and measures", which have been regulated since quite early in U.S. history as an anti-fraud measure (e.g. butchers were traditionally required to use an officially certified scale).