US Gallon
The US gallon is a unit of volume equal to 128 US fluid ounces, 4 US quarts, or approximately 3.785 liters. It is the standard unit for measuring fuel and large liquid volumes in the United States.
History
The US gallon is derived from the English wine gallon of 231 cubic inches, which was adopted by the United States in 1832. It differs from the imperial gallon (4.546 liters) used in the United Kingdom. The US gallon is most commonly associated with gasoline pricing in America.