Tariffs were very strong American worker wage protection, HENCE corporations hate tariffs.

[brentspeak]

36. Uh, we import crude when we really don't need to

Refining our own crude for sale overseas as petroleum products, and importing crude for sale on the domestic market and for petroleum refinement. We produce sufficient crude to satisfy domestic demand, but too much of it gets exported.

http://www.eia.gov/tools/faqs/faq.cfm?id=268&t=6

How much of the oil produced in the United States is consumed in the United States?

EIA cannot determine exactly the amount of crude oil produced in the United States (U.S.) that is consumed, as refined products, in the U.S. However, the majority of the crude oil produced in the U.S. is refined in U.S. refineries. The U.S. also produces other liquids that are used in the refining process that are added or blended with the refined products. In December 2012, the U.S. produced about 7.03 million barrels of crude oil per day and imported about 7.58 million barrels per day.

EIA is not able to track how much domestically produced crude oil and other liquids are exported in the form of refined products. The small quantity of crude oil produced in the U.S. that is exported, nearly all to Canada, may actually be returned to the U.S. as refined products.

The U.S. became a (slight) net exporter (exported more than we imported) of refined petroleum products in 2008. Refined petroleum products produced in the U.S. from both domestic and imported crude oil are exported to other countries. The volume of net exports of refined products in December 2012 was equivalent to about 8.5% of the total volume of U.S. petroleum consumption in December 2012.