Fueling Our Nation

In 2021, fuel (HTS 27) accounted for about 50 percent of U.S. ex-/imports by vessel, of which crude oil (HTS 2709) is the leading commodity.[1] The U.S. imported about 2.2 billion barrels of crude oil in 2021, up about 82 million (3.8 percent) from 2020. A standard U.S. barrel contains 42 gallons of crude oil, which in turn yields about 44 gallons of petroleum products. About 19 gallons (43 percent) of gasoline, 10 gallons (23 percent) of diesel fuel, 4 gallons of jet fuel (9 percent), and 11 gallons of other products (25 percent) are refined from a single barrel of crude oil.[2]
Crude oil, which is refined into gasoline, diesel, jet fuel, and other products are primarily ex-/imported by pipeline, rail, or truck from Canada or Mexico. However, tanker vessels almost exclusively move crude oil and refined petrochemicals to and from other countries around the world (e.g., Saudi Arabia, Russia, etc.).
As shown in 1st tab of the figure below Canada is by far the Nation's number 1 source of crude oil, accounting for about 1.4 billion barrels of crude oil (61.3 percent), followed by Mexico with about 212 million (9.5 percent) in 2021. Other leading sources of crude oil include Saudi Arabia, Russia, and Columbia (as shown in 2nd tab of the figure below). 
According to the U.S. Energy Information Administration, more than 47 percent of total U.S. petroleum refining capacity and 51 percent of total U.S. natural gas processing plant capacity are along the Gulf Coast.[3] This region has the Nation's top maritime ports for U.S. crude oil imports and by tonnage, including 6 ports in Texas (Beaumont, Corpus Christi, Freeport, Houston, Port Arthur, Texas City) and 3 ports in Louisiana (Baton Rouge, Lake Charles, New Orleans) as shown in the 2nd tab in the figure below. In 2020, Houston was the top maritime port for U.S. crude oil imports and for total tonnage.[4]  
As shown in the figures below, U.S. ex-/imports of fuel (HTS 27) by value decreased significantly during 2nd quarter 2020, beginning in April 2020, at the start of the COVID-19 pandemic. In 2021, U.S. ex-/imports of fuel by value increased by about $181 billion (66 percent) from 2020. The U.S. exports and imports comparable amounts of fuel by value. However, the U.S. imported more fuel from Canada and Mexico than it exported, whereas we exported more to the rest of the world than we imported.[5] 
Vessels account for almost 100 percent of the U.S. ex-/imports of fuel (HTS 27) by value from/to rest of the world. In 2021, according to BTS Transborder Freight Data, vessels accounted for only $184 billion (31 percent) of the U.S.-Canada and Mexico ex-/imports of fuel. Of this, the U.S.-Canada accounts for about $126 billion (68 percent) of the ex-/imports of fuel, and Mexico accounts for about $58 billion (32 percent). In 2021, the top U.S. import from Canada was fuels ($103.2 billion).
Pipelines were the leading mode of transportation between the U.S.-Canada and Mexico, transporting about $98 billion in 2021, up from $53 billion (85 percent) in 2020. Pipelines were followed by vessels with about $60 billion (31 percent), rail with about $19 billion (10 percent), and trucks with $12 billion (6 percent).[6] 
For additional data and analysis from the BTS Transborder Freight Data program, please visit the following webpage: Transborder Freight Data | Bureau of Transportation Statistics (bts.gov)
In recent years, U.S. imports of crude oil have been declining as shown above, but the demand for/supply of gasoline has declined to a lesser extent. In turn, gasoline supply and prices have increased from the low set in April 2020 (as shown in the figure below), which corresponds with a low in demand for/supply of gasoline at start of the global COVID-19 pandemic.[7]
Tankers, including chemical tankers, oil tankers, and gas carriers, are one of the vessel types for which the BTS Port Performance Freight Statistics Program calculates dwell times and are the 2nd most common vessel type in maritime trade & transportation. The average tanker vessel dwell times at 21 of the top U.S. ports by tonnage was estimated at 41.4 hours in 2020, down almost two hours from 43.3 hours in 2019.[8]
For dwell time data and analysis, please visit the following webpage: Tanker Vessel Dwell Times (bts.gov). Additionally, tanker vessel dwell times for individual ports are shown in the online Port Profiles.  
Footnotes
[1] NOTES: Harmonized Tariff Schedule Chapter 27 (HTS 27) Mineral fuels, mineral oils and products of their distillation; bituminous substances; mineral waxes. HTS 2709 Petroleum oils and oils obtained from bituminous minerals, crude. Conversion Factor: Kilograms to Short Tons =  907.18474. SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics analysis of U.S. Census Bureau, Economic Indicators Division, U.S. Import and Export Merchandise Trade Statistics, available at USA Trade Online * Home (census.gov) as of March 2022.
[3] U.S. Department of Energy, Energy Information Administration, available at Gulf of Mexico Fact Sheet - Energy Information Administration (eia.gov) as of March 2022.
[4] U.S. Department of Transportation, Bureau of Transportation Statistics, analysis based upon: Crude Oil: U.S. Department of Energy, Energy Information Administration, available at Crude Imports (eia.gov) as of March 2022. Tonnage: 2020 data, U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center, special tabulation as of December 2021. 
[5] NOTE: Harmonized Tariff Schedule Chapter 27 (HTS 27) Mineral fuels, mineral oils and products of their distillation; bituminous substances; mineral waxes. SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics analysis of U.S. Census Bureau, Economic Indicators Division, U.S. Import and Export Merchandise Trade Statistics, available at USA Trade Online * Home (census.gov) as of March 2022.
[6] U.S. Department of Transportation, Bureau of Transportation Statistics, 2021 North American Trade Value Reaches $1.3 Trillion, up 8% from Pre-pandemic 2019, up 25% from 2020; available at https://www.bts.gov/transborder as of March 2022.
[7] U.S. Department of Energy, Energy Information Administration, All Grades of Gasoline, U.S. City Average Retail Price ($ per Gallon, Including Taxes), available at U.S. Gasoline and Diesel Retail Prices (eia.gov) as of March 2022.
[8] U.S. Department of Transportation, Bureau of Transportation Statistics, calculated using AIS data from the U.S. Coast Guard’s Nationwide Automatic Identification System (NAIS) archive, processed by U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, through the AIS Analysis Package (AISAP) software package as of December 2021.