U.S. fuel costs for diesel hit a new peak on Sept. 20, with the median price reaching $6.39 per gallon. GasBuddy data showed the top 10% of stations averaged $7.01 per gallon, while the bottom 10% averaged $5.83 per gallon. These figures highlight the current price volatility facing commercial fuel buyers and agricultural operators.

Senator Chuck Grassley urged President Donald Trump to embargo diesel exports after Iowa prices reached $6.57 per gallon. A power outage forced the shutdown of ExxonMobil's refinery in Joliet, Illinois, which accounts for about 6% of Midwest refining capacity. GasBuddy's Patrick De Haan said there are no widespread diesel shortages in the U.S. currently, though further retail price increases are expected.