What the record-high cost of diesel means for you

Diesel prices hit an all-time high of $5.98 a gallon as of September 10, up about $2.31 since late February, when the war between the United States, Israel, and Iran began. In California, diesel now costs $7.91 a gallon. The war has largely closed the Strait of Hormuz, a shipping route that once carried 10 percent of the world's seaborne diesel, and Ukraine's attacks on Russian refineries have added to the squeeze. U.S. refineries are already running at full capacity, and domestic fuel inventories are at their lowest level since 1982.

Most households don't buy diesel directly, but they feel it through higher prices at the store, since diesel powers the trucks and ships that move most goods. Rising diesel and gas prices together have cost U.S. households an average of about $350 this year, according to a Brown University tracker.

The bigger concern for many homeowners is winter heating. Heating oil is essentially diesel, and the millions of households that use it, mostly in the Northeast, could see unusually high bills this season. That risk is sharper because the Trump administration has proposed eliminating the Low Income Home Energy Assistance Program, which helps cover fuel costs for lower-income households. Experts say even if the wars driving up prices ended immediately, it would take weeks or months for diesel supplies and prices to return to normal.