US diesel hits record $6.51 amid #Iran war US diesel prices have climbed to a record $6.51 per gallon , up more than 73% since the war with Iran began in February , KSHB41 reported. The outlet cited disruptions linked to the US aggression against Iran and wider instability in the Middle East among the factors driving prices higher. Republican Sen. Chuck Grassley has urged the #Trump administration to halt diesel exports