The fuel that moves America's freight is easing slightly, but it remains painfully expensive. The national average for diesel was about $6.37 a gallon on Oct. 3, according to AAA, as reported by CDL Transportation Group. That is about $2.67 more than a year earlier.

Government data show a similar picture. The Energy Information Administration recorded a record $6.529 a gallon for the week of Sept. 21, FleetOwner reported. The next week, the average dipped to $6.382.

Diesel powers most trucks, trains, tractors and ships. When it costs more, the cost of moving almost everything goes up. Trucking companies often add fuel surcharges to their bills, and those charges show up later in the price of groceries and goods.

Why is diesel so high? The war with Iran disrupted oil shipments through the Strait of Hormuz and pushed crude prices above $100 a barrel. Diesel is also tight because refineries can make only so much of it, and demand rises in the fall when farmers harvest and heating oil season starts.

Small trucking firms feel it most. Many owner-operators run on thin margins and cannot pass on every increase.

For context, diesel's previous record was set in June 2022, after Russia invaded Ukraine. Prices then fell for most of the next three years before this year's surge.

Gasoline has also eased. AAA's national average for regular was about $4.37 Monday, down from records set in September.

Relief may depend on the Gulf. Middle East exports have recovered to prewar levels on some days, and the Group of Seven plans to release emergency oil stocks.

What we know: Diesel is down from its record but still near $6.40 a gallon.
What we don't: Whether prices will keep falling into winter.