Forget gasoline: This overlooked fuel could raise the price of nearly everything you buy

• The Strait of Hormuz closure, through which 20 million barrels of oil pass daily, is the primary driver of diesel price increases over the past five months
• A fully loaded semi-truck gets only 6-7 miles per gallon and costs over $1,280 to fill at current prices, with these transportation costs passed through the supply chain
• Diesel price impacts may persist even after geopolitical tensions ease due to refining lag times, with fuel sold today potentially processed weeks or months earlier

Summary

Key Development: Diesel fuel prices have surged 44% from $3.56/gallon in January 2025 to $5.13/gallon following the escalating U.S.-Iran conflict, according to the U.S. Energy Information Administration.

Economic Impact: Unlike gasoline, diesel is the "workhorse fuel" powering America's supply chain—from semi-trucks and freight trains to agricultural equipment and irrigation pumps. The price spike threatens to increase costs across nearly all consumer goods, particularly food and deliveries.

Transportation Costs: A fully loaded semi-truck averages just 6-7 miles per gallon. With typical 250-gallon fuel tanks, a single fill-up now costs over $1,280, representing a significant increase in transportation expenses that businesses typically pass to consumers.

Geopolitical Factor: Industry sources attribute most of the five-month price surge to the closure of the Strait of Hormuz, a critical waterway through which 20 million barrels of oil pass daily. This chokepoint between Iran, Oman, and the UAE remains vulnerable to ongoing Middle East tensions.

Expert Analysis: Bernard Yaros, lead U.S. economist at Oxford Economics, expressed particular concern about inflationary pressures on grocery prices. "Diesel powers the irrigation pumps, the tractors in the field and the trucks that bring food from the farm to your local grocery store. It's part of every layer of food production," he noted.

Market Outlook: Even if geopolitical tensions ease, diesel prices may remain elevated due to refining lags. Fuel being used today was often refined 1-2 weeks ago from crude oil produced two months prior, meaning higher costs will continue rippling through the economy well after conflicts subside.