Melius Research says a disruption at the Strait of Hormuz would pose a particularly acute challenge for aviation fuel markets, with jet fuel flows far more constrained than crude oil.
Historically, roughly 20 to 21 million barrels per day move through the strait. Of that total, about 3 million barrels per day consist of refined products. Within those refined flows, aviation-grade fuel is the most tightly constrained component because crude oil has alternative routing options that jet fuel effectively lacks.
Jet fuel must be produced from certain feedstocks at specific refinery units and then moved into a distribution network that centers on hubs such as Amsterdam-Rotterdam-Antwerp (ARA), Singapore, and the Gulf. Those hub inventories are already below their seasonal norms, leaving limited buffer if flows are interrupted.
Feedstock quality presents a practical limit on substitution. Jet A-1 requirements are fixed by physics and engine tolerances, and refiners cannot simply swap crude grades without physical changes to their plants. European refiners currently processing 20% to 25% Arab Light would not be able to switch to West African crude or U.S. light sweet barrels without hardware modifications to their facilities.
Refinery maintenance and restart timelines compound the problem. Planned turnarounds typically last between 2 and 6 weeks, while a cold restart of a fully idled refinery can take 4 to 12 weeks. Those timelines mean that any attempt to bring additional refining capacity online in response to a disruption would not be immediate.
Regulatory and logistical workarounds are being considered but are not yet operational. The European Union is assessing whether importing Jet A - the U.S. specification of aviation fuel - could serve as an emergency backstop. That route would require regulatory changes and is not currently in place.
On the inventory side, aggregate jet stocks stand roughly 7 million barrels below the five-year seasonal average, and ARA hub stocks are at a six-year low. The Middle East, excluding Iran, has about 18 days of coverage, the tightest level among the tracked regions and the one most directly exposed to a disruption of flows through the Strait.
Europe is sliding beneath its five-year average and remains structurally short on refining capacity to self-correct. Strategic petroleum reserves are arranged to hold crude oil rather than refined products, so they do not provide a ready buffer for jet fuel shortages.
Regional dynamics add complexity. OECD Americas recently reached a multi-year high in product inventories, but those stocks largely serve domestic markets and do not necessarily represent barrels positioned for export. OECD Europe has been below its five-year average for nearly the entire period since 2021. Asian refineries depend on the Gulf for roughly half of their crude feedstock.
China introduced export restrictions to protect domestic supply but, according to the same reporting, is poised to likely resume exports in May. That potential development could affect the balance of flows but does not eliminate the structural constraints on jet fuel production and distribution described above.
Bottom line: A disruption of the Strait of Hormuz would disproportionately strain jet fuel availability because of limited feedstock substitutability, constrained hub inventories, and long lead times to restore refining capacity.