Dry gallon measure of approximately the same size, though the dry gallon is a bit bigger. 1 dry gallon ≈ 1.163 647 fluid gallons Its implicit value in the US system was originally one eighth of the Winchester bushel, which was a cylindrical measure of 18.5 inches in diameter and 8 inches in depth. That made the dry gallon a non-terminating number of cubic inches, an irrational number whose value with the first six digits after the decimal point was 268.802521 ( cubic inches ≈ ). The bushel was later defined to be exactly 2150.42 cubic inches, making the dry gallon exactly
Gallon in fuel economy expression in Canada and the United Kingdom are imperial gallons. Despite its status as a U.S. territory, and unlike American Samoa, the Northern Mariana Islands, Guam, and the U.S. Virgin Islands, Puerto Rico ceased selling gasoline by the US gallon in 1980. The gallon was removed from the list of legally defined primary units of measure catalogued in the EU directive 80/181/EEC for trading and official purposes, with effect from 31 December 1994. Under the directive the gallon could still be used – but only as a supplementary or secondary unit. One of the effects of this