US oil barrels
A US oil barrel, also known as a petroleum barrel, is a volume unit used in the oil and gas industry to measure crude oil or liquid petroleum gas (LPG). One US oil barrel is 42 US gallons or about 159 liters.
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.