Diesel prices have been climbing for weeks as the standoff around the Strait of Hormuz disrupts crude and fuel flows, and jet fuel is now following the same path, according to MarketWatch reporting on the session of September 22, 2026. Refiners already squeezed by the supply shock are struggling to meet demand for both fuels at once, a dynamic that has pushed prices for the aviation industry's key input higher just as diesel costs strain truckers and farmers.
Adding to the uncertainty, Iranian state media reported that Iran has laid out conditions for reopening the Strait of Hormuz, the narrow waterway through which a large share of the world's seaborne oil and gas passes. Separately, President Trump said his administration is considering a ban on diesel exports and that a decision is coming "fast, one way or the other," a move that could keep more diesel supply at home but risks retaliation from trading partners who rely on US barrels.
What remains unresolved is which lever moves first: an Iranian reopening of Hormuz that eases the underlying supply shock, or a US export ban that addresses domestic diesel prices but does nothing for the global squeeze feeding into jet fuel costs.