US motorists are entering the peak summer driving season amid tightening gasoline supplies, as sustained domestic demand and rising fuel exports put pressure on already thin inventories. Despite higher pump prices—averaging over $4 per gallon and up about 40% since the start of the Iran war—gasoline consumption remains robust, raising concerns about potential supply shortfalls.
US refiners have shifted focus toward increasing production of diesel and jet fuel to offset global shortages triggered by disruptions at the Strait of Hormuz, a critical oil transit point that has effectively closed since the onset of the conflict in Iran. The passage accounts for nearly 20% of global oil flows, and its closure has heightened the urgency to meet global demand for distillate fuels.
The domestic gasoline supply buffer, built up during the low-demand winter months, was largely depleted by the end of May, coinciding with the Memorial Day holiday that traditionally signals the start of the summer travel season which lasts through early September. Gasoline inventories fell to 215.1 million barrels in early June, the lowest seasonal level recorded in a decade, reflecting a decline of more than 34 million barrels since the war began. Distillate fuel oil stocks, which include diesel and heating oil, dropped to their lowest point in 23 years as of May, underscoring the vulnerability of the market to further disruptions.
Analysts estimate that US demand for refined fuels could reach approximately 9.5 million barrels per day during the summer, surpassing current refinery output capacity of around 9.2 million barrels per day. This imbalance is compounded by incentives for refiners to prioritize jet fuel amid global shortages, with Middle Eastern refiners unlikely to restore output soon due to ongoing disruptions.
US refiners are comparatively insulated from the Strait of Hormuz blockade, sourcing less crude from the region than their Asian and European counterparts. This has enabled them to maximize distillate production, with jet fuel output hitting a record average of over 2 million barrels per day in late April. Exports of diesel and jet fuel reached 54.65 million barrels in May, the highest monthly volume since 2017, while gasoline exports also rose to 22.52 million barrels in May from 20.10 million barrels in April.
The shift toward distillate fuels has left gasoline supplies strained. The United States historically relied on imports from Europe to balance regional gasoline deficits, but current logistical challenges and tight European fuel stocks, compounded by elevated freight rates due to the blocked shipping route, have diminished this option.
Analysts warn that gasoline inventories could be drawn down by as much as 2 to 3 million barrels per week during the summer peak. Refinery runs have remained high, operating at 95.3% capacity in early June—the highest level in nearly a year—but there are growing concerns about maintenance delays and unplanned outages. April saw the highest average unplanned refinery outages in five years, with about 483,000 barrels per day of crude processing capacity offline.
Some planned maintenance originally scheduled for the fall has reportedly been deferred or reduced in scope to maintain output, though industry experts caution that postponing such work could lead to operational risks down the line. As the summer progresses, the balance between strong fuel demand and refinery capacity constraints will be closely monitored amid ongoing geopolitical tensions and shipping disruptions.