U.S. Retail Diesel Prices Hit Record High as Global Supply Tightens

U.S. diesel prices jumped to a fresh record high as prolonged disruptions to Middle East energy flows and Russian refineries continue to tighten global supplies ahead of peak-demand season.

The national average price of diesel hit $5.850 a gallon on Friday, the highest on record, according to the American Automobile Association. A year ago, prices averaged $3.712 a gallon.

Russia—traditionally one of the world's largest exporters of refined fuels—has cut domestic fuel production and restricted diesel exports following sustained Ukrainian attacks on its refineries. In the Middle East, the war has curtailed flows through the Strait of Hormuz, a critical waterway carrying large volumes of Gulf oil and refined products.

The disruptions are prompting more buyers to turn to the U.S., giving American producers an incentive to maximize diesel output and exports. That competition is lifting the value of U.S. diesel and widening refiners' margins, with the higher costs ultimately flowing through to retail prices.

Refiner profit margins for making diesel from crude oil in the U.S.—known as the diesel crack spread—breached the $100-a-barrel mark for the first time in August.

Diesel is a key part of the global economy, fueling trucks that move food and manufactured goods, heavy equipment at construction sites and ships at sea. It is also widely used for heating. A prolonged supply crunch can ripple through the economy, pushing up freight rates and the cost of food, construction and household fuel.

The timing is unfavorable. Across the Northern Hemisphere, farmers consume large quantities of diesel during harvest season to power tractors, combines and other machinery, while colder weather later in the year typically boosts demand for heating fuels. Refineries are also scheduled to undergo seasonal maintenance in the fall, taking some processing capacity offline just as demand begins to rise.

Write to Giulia Petroni at giulia.petroni@wsj.com