Fermi Estimate: America's Annual Petroleum Imports, Gross and Net

Estimate how many barrels of oil the United States brings in from other countries each year, talking through your reasoning as you go. ```hint Work back from demand There is no tanker count you can rebuild from memory. Think about where the country uses oil, how much of that it supplies itself, and whether oil also leaves the country. ``` ### Clarifying Questions - Do you want gross imports, or net imports after subtracting what the US exports? - Should I count crude oil only, or crude plus refined products such as gasoline, diesel and jet fuel? - Is a recent typical year fine, and do you want an order of magnitude or a tighter range? ### What a Strong Answer Covers - A clear definition of the quantity (gross or net, crude or all petroleum) before any arithmetic - An equation that links imports to consumption and domestic supply, instead of treating fuel use as imports - A consumption estimate that covers cars and the other large uses: trucking, aviation, industry and petrochemicals - Clean units (gallons to barrels, per day to per year) with round, labeled assumptions - A sanity check, a stated range, and the assumption that moves the answer most ### Follow-up Questions - How would your answer change if I asked for net imports instead of gross? - If a quarter of passenger vehicles were electric, how much would imports fall, and why might the drop differ from the drop in gasoline demand? - Which assumption are you least sure about, and how would you check it quickly?