In recent years, higher domestic production of light, tight crude oil has led to a reduction in crude oil imports . Certain types of crude oil have been affected more than others; for example, the increased economic availability of domestic light, tight crude oil has virtually eliminated Gulf Coast imports of light crude oil. In the past year, Gulf Coast imports of medium crude oil have also fallen because of increased production from the Eagle Ford , Bakken , and Permian regions. One of the key characteristics of crude oil is its density, measured by API gravity as established by the American Petroleum Institute . Less-dense liquids have higher API gravities. Crude oils with API gravities of 35 or above are considered light; 27 to 34 are medium; less than 27 are […]