Iran War Cuts More Diesel Supply Than Russia Conflict Did

How much diesel supply has the Iran war removed?

The Iran war has removed more diesel supply from global markets than the Russia-Ukraine conflict did, according to estimates compiled by Bloomberg and confirmed with diesel traders. The finding comes as U.S. diesel prices hit $6.33 per gallon, 50 cents above the previous all-time high set in 2022.

The supply loss matters because diesel is the fuel that moves freight. Every gallon a carrier burns comes straight off the settlement statement, and the Iran conflict has now cut deeper into global refining capacity than the sanctions and disruptions that followed Russia's invasion of Ukraine in February 2022.

Bloomberg's analysis, cross-checked with diesel traders, puts the Iran war's impact on diesel availability ahead of the Russia-Ukraine disruption. The Russia conflict triggered diesel price spikes in 2022 when European buyers scrambled to replace Russian product and U.S. inventories fell to multi-year lows. The current Iran war has now surpassed that threshold.

The Iran conflict has shut down refining capacity in the Persian Gulf and disrupted shipping through the Strait of Hormuz, the chokepoint that handles roughly 20% of global oil flows. Saudi Arabia shut down a major pipeline in response to regional attacks, and multiple refineries in the Gulf have curtailed diesel production due to security concerns and damage from strikes.

What the supply loss costs small fleets

A five-truck fleet running 500 miles per day per truck at 6 miles per gallon burns roughly 417 gallons per day. At $6.33 per gallon, that's $2,640 daily in fuel, or $79,200 per month. The same operation paid $4,950 per day, or $148,500 per month, when diesel averaged $5.00 per gallon in early 2024. The difference is $1,690 per day, or $50,700 per month, before fuel surcharges.

Fuel surcharges tied to the Department of Energy's weekly diesel index have climbed in step with pump prices, but contract rates have not kept pace. Spot rates remain under pressure from weak freight demand, leaving owner-operators and small fleets squeezed between record fuel costs and flat or declining linehaul revenue.

The Iran war entered its sixth month in early September, and Brent crude hit $97.85 per barrel as fighting intensified. Crude prices have since topped $105 per barrel, with diesel tracking higher. Energy analysts warn that sustained conflict in the Gulf could push diesel to $7 to $9 per gallon by November if refinery outages persist and Hormuz flows remain constrained.

Why this supply shock runs deeper than 2022

The Russia-Ukraine war disrupted diesel flows primarily through sanctions and European buyer shifts. Refineries in Russia continued to operate, and product found alternative buyers in Asia and the Middle East. Global refining capacity remained largely intact, even as trade routes shifted.

The Iran war has physically removed refining capacity from the market. Gulf refineries have shut down or cut runs due to strikes, security threats, and damage to infrastructure. The Saudi pipeline shutdown eliminated a key bypass route around Hormuz, forcing more tanker traffic through the strait at a time when insurance costs and security risks have spiked.

Diesel inventories in the U.S. have fallen below the five-year average for the third consecutive week, according to Energy Information Administration data. East Coast stocks, which supply the I-95 corridor and major freight lanes, are at their lowest September level since 2019. The combination of tight domestic supply and constrained imports from the Gulf has left little cushion for further disruptions.

What changes for carriers

Small fleets and owner-operators face a fuel cost environment worse than the 2022 spike, with less freight volume to spread the expense across. Contract rates have held flat for three months running, and spot rates per mile remain 6% below year-ago levels in most lanes. The math does not work without fuel surcharges that fully cover the pump price increase, and many shippers are capping surcharge escalators or negotiating fixed fuel components into contracts.

Fleets running older equipment are looking hard at natural gas trucks, which now pay back in under three years for carriers replacing pre-2013 diesels. Renewable natural gas prices have held steady while diesel has spiked, cutting the payback window by more than a year compared to early 2024 projections.

The Iran conflict shows no signs of resolution, and diesel supply will remain tight as long as Gulf refineries stay offline and Hormuz flows face disruption. Carriers planning fall and winter operations should budget for sustained high fuel costs and limited rate relief until either the conflict de-escalates or alternative refining capacity comes online to replace the lost Gulf production.