Diesel jumps 20 cents as Brent tops $106 on Iran tanker threats

Diesel spot prices jumped 20 cents in a matter of hours, and the bodies that track inventory say stocks are thin enough that one source told FreightWaves the market is "running out of bullets." Brent is $106.37 and WTI is $94.72, both up after Iranian officials told Reuters they plan to intensify strikes on tankers moving through the Strait of Hormuz with new tactics. If you buy product on a rack-plus deal, that move already hit your cost this morning.

The Hormuz threat

Iran is not talking about closing the strait. It is talking about hitting more ships inside it, which does something worse for your supply than a clean shutdown would. Insurers reprice, owners hold vessels back, and the crude still has to move. Israeli media reported Netanyahu asked Trump to resume bombing Iran, and the Houthis confirmed they targeted several Aramco refineries, with reports of severe explosions in Jeddah near the Aramco plant there. Refining capacity getting hit matters more to your diesel cost than barrels in the ground, because the world is short product, not just crude.

Stranded Canadian heavy

Tanker rates are at all-time highs, and the shortage of ships is tipping the heavy crude market in North and South America into oversupply while Asia and Europe go short. Canada produces over 5 million barrels a day, most of it heavy, and about 4 million of that runs south to US refineries. That pipeline-fed heavy crude is cheap right now relative to waterborne grades, which is a rare piece of good news for Gulf Coast and Midwest refiners who can run it. Coastal plants that import heavy by ship do not get that break.

Refinery margins

European refining margins collapsed as input costs soared, per the Financial Times, and that pulls product toward Europe and away from the US export arbitrage math. One analysis put the blame for high pump and rack prices on refinery problems as much as crude supply, which squares with what the 20-cent diesel move is telling you. Separately, Zelenskyy confirmed the US threatened to cut intelligence-sharing over Ukrainian strikes on Russian refineries, another sign Washington wants fewer barrels of refining capacity taken offline anywhere.

One forecaster still sees Brent and WTI heading lower from here, so the futures curve and the cash market are not telling the same story.

What to watch

The tanker threat is the one to track: if it turns into actual hits inside Hormuz, that pushes rates and crude higher. Distillate inventory numbers will show whether the tightness the spot move implies is real. The Jeddah refinery reports still need to be confirmed as actual damage. If the strait stays open and no more Aramco plants go down, diesel could give some of this back.