Cubic inches
Cubic inches are units of volume measurement used in the Imperial systems equal to the volume of a cube with sides that are each one inch in length. It is used in the United States for measuring small volumes, such as the displacement of an engine or the capacity of a container. One cubic inch is equivalent to approximately 16.387 cubic centimeters.
US liquid gallons
A US liquid gallon is a volume measurement used in the United States for liquids such as water, gasoline, and milk. One US liquid gallon is about 3.78541 liters. A standard bathtub is about 80 gallons of water and a car gas tank can hold anywhere between 12 and 20 gallons of gas.