The national average on-highway diesel price rose to $5.454 per gallon for the week ending August 17, 2026, according to data the U.S. Energy Information Administration released on August 18. The weekly move was an increase of roughly 20 cents, and the price sits $1.741 above where diesel stood one year earlier.
The climb caps a steep run over a short period. The current average is close to 38 cents higher than one month ago and represents a large increase from the roughly $3.69 per gallon recorded at the same point in 2025.
Supply data helps explain the move. EIA reported that distillate fuel inventories fell by 1.5 million barrels in the most recent reporting week and now sit about 13 percent below the five year average for this time of year. Distillate covers both on-highway diesel and heating oil, so inventory pressure in that category feeds directly into pump prices for commercial fleets.
The diesel market also crossed a notable threshold this month, with U.S. diesel topping $100 per barrel on a wholesale basis for the first time. Refinery closures announced over the past two years have removed domestic production capacity, and utilization at remaining plants has run near the top of its historical range with limited spare room to absorb demand spikes.
Carriers operating under fuel surcharge programs recover a portion of the increase, though the lag between the EIA weekly benchmark and surcharge resets leaves a gap that falls on the operator.
Source: FleetOwner - https://www.fleetowner.com/emissions-efficiency/news/55398818/diesel-prices-surge-as-us-diesel-market-tops-100-per-barrel-for-first-time