Diesel fuel in the Charlotte metro area hit an all-time high of $6.17 per gallon on Tuesday, Sept. 15, according to AAA data.

That price is nearly $3 more per gallon than a year ago, WBTV first reported. At a west Charlotte truck stop, diesel reached nearly $6.40 per gallon the same day.

Ballantyne shoppers at Blakeney, Waverly and Stonecrest could feel the effects. Diesel powers the trucks that stock grocery shelves, deliver restaurant supplies and move packages to front doors. UNC Charlotte economics professor Matthew Metzgar said the surge acts like a hidden cost that businesses must either absorb or pass along to customers.

"It's almost like a hidden tax, so to speak," Metzgar told WBTV.

He said businesses face a choice between accepting lower profit margins or raising prices on the goods they bring in. Metzgar attributed the spike to disruptions in global shipping routes stemming from the U.S. war with Iran.

The national average for diesel reached $6.06 per gallon on Saturday, Sept. 12, up from $5.85 the prior week, according to WCCB Charlotte's reporting on AAA data. Before the U.S. and Israel launched the war against Iran in late February, the national average sat at about $3.76. American diesel prices are now more than 60% above pre-war levels.

Fuel accounts for roughly 15% to 30% of the total cost of food, according to the Independent Grocers Alliance. Refrigerated items tend to see price increases first. In July, overall U.S. grocery prices were up 2.7% compared to a year earlier, but seafood prices rose 7% and fresh fruit climbed 4.9%, Michigan State University food economics professor David Ortega told WCCB.

Burnie Davis, an independent truck driver who hauls merchandise for major big-box retailers, told WBTV that drivers are absorbing the cost for now but grocery shoppers are already seeing prices climb.

Shipping surcharges are already spreading. Amazon rolled out a temporary 3.5% fuel and logistics surcharge on some third-party sellers in April. UPS, FedEx and the U.S. Postal Service also added fees on some packages, WCCB reported.

Regular gasoline in Charlotte is climbing too. The average reached $3.95 per gallon on Monday, Sept. 14, up nearly 12 cents in a week, according to a GasBuddy survey reported by WFAE. GasBuddy analyst Patrick DeHaan pointed to escalating geopolitical tensions, including hostilities in the Red Sea and the shutdown of Saudi Arabia's East-West pipeline.

S&P Global Energy said in September it does not project Middle East crude oil production to return to pre-war levels by the end of 2027.