U.S. diesel prices reached an all-time high of $6.31 a gallon this week, with the Energy Information Administration reporting a national on-highway average of $6.285 on September 14. The increase is squeezing truckers, particularly owner-operators and small carriers, while J.B. Hunt expects at least a $10 million earnings headwind. Higher diesel costs are moving through freight rates, food delivery, farm equipment, home heating and retail prices, with the effects taking several weeks to reach consumers. Heating-oil users in the Northeast could face bills as much as 31% higher this winter if prices remain elevated. Gasoline also rose to $4.43 a gallon nationally, while California diesel averaged $8.04. Supply disruptions linked to the conflict with Iran and damage to refining capacity in Russia and the Middle East have tightened fuel markets. Although Saudi Arabia's efforts to reroute crude exports through Oman pushed oil prices lower, experts say diesel remains constrained mainly by refining capacity rather than crude supply.