Source: U.S. Energy Information Administration,

Notes: Net exports equal gross exports minus gross imports. Negative net export values indicate net imports.

U.S. Energy Information Administration, Petroleum Supply Monthly Net exports equal gross exports minus gross imports. Negative net export values indicate net imports.

The United States in 2011 exported more petroleum products, on an annual basis, than it imported for the first time since 1949, but American refiners still imported large, although declining, amounts of crude oil, according to full-year trade data from EIA's Petroleum Supply Monthly February report. The increase in foreign purchases of distillate fuel contributed the most to the United States becoming a net exporter of petroleum products.

U.S. petroleum product net exports (exports minus imports) averaged 0.44 million barrels per day (bbl/d) in 2011, with imports at a nine-year low of close to 2.4 million bbl/d and exports at a record high of nearly 2.9 million bbl/d. The gap between exports and imports widened the most during the second half of the year from August through December (see charts below), with total monthly exports topping 3 million bbl/d for the first time.

Source: U.S. Energy Information Administration,

U.S. Energy Information Administration, Petroleum Supply Monthly

Strong global demand helped propel distillate exports, as distillate fuel, which includes diesel, had a higher profit margin for U.S. refiners than gasoline. Refiners also had access to increased supplies of crude oil imports from Canada, which in 2011 topped 2 million bbl/d for the first time, and from North Dakota's Bakken formation to process into petroleum products.

The United States remained a net importer of crude oil, some of which was refined into petroleum products that were then exported. Petroleum products were ranked second in value of all U.S. exports during 2011 at $111.1 billion, up 60% from 2010, according to U.S. Department of Commerce trade data. Vehicles were the number one U.S. export last year at $132.5 billion. Crude oil was the biggest U.S. import, valued at $331.6 billion, up 32% from 2010. Rising crude oil prices, rather than higher crude oil import volumes, were the key driver of the increased value of crude oil imports.