The US Energy Information Administration projects that on-highway diesel fuel prices will average $4.76 per gallon for 2026, with prices trending downward through the second half of the year. The agency's Short-Term Energy Outlook forecasts diesel averaging $5.36 per gallon in the second quarter, easing to $4.94 in the third quarter and $4.73 in the fourth quarter.
Weekly EIA data showed diesel prices hovering near $5.60 to $5.64 per gallon in mid-May before beginning their projected decline. Analysts attribute the anticipated easing to softer crude oil costs, though they caution that geopolitical instability in regions that supply crude oil or refined petroleum products could set a floor under both wholesale and retail diesel prices for the remainder of the year.
For fleet managers, the forecasted decline offers some relief on operating costs after diesel prices remained elevated through much of the first half of 2026. Fuel costs remain one of the largest line items in fleet budgets, and even modest per-gallon changes translate into significant swings in total operating expense across a large truck fleet.
Source: Transport Topics -- https://www.ttnews.com/articles/diesel-price-forecast-2026