# DOE Number Falls 4.3 Cents to $5.596/gal _May 18, 2026_ > The DOE number fell 4.3 cents to $5.596/gal for the week of May 18, trimming about $3.31 from a 500-mile haul at the stated 6.5 mpg reference. The index is 46% above its 5-year median. The DOE number (EIA's weekly on-highway diesel survey) fell **4.3 cents** to **$5.596/gal** for the week of May 18. At the stated 6.5 mpg reference, the index runs **86.1 cents a mile** and the week's drop trims about **$3.31** from the fuel cost of a 500-mile haul. The index remains **46% above its 5-year median** for this calendar week. [Chart: Diesel fuel cost per mile (at 6.5 mpg)](https://mondaydiesel.com/costpermile/diesel-cost-per-mile) ([data](https://mondaydiesel.com/costpermile/diesel-cost-per-mile.md) — chart image: https://mondaydiesel.com/charts/costpermile/diesel-cost-per-mile/chart.png) - Rocky Mountain (PADD 4), **$5.549/gal**, up 1% on the week: the one region in the EIA survey to move against the national trend. - Midwest (PADD 2), **$5.749/gal**, down 1%: running 53% above its 5-year median, the widest vs-normal gap of any surveyed region, with spring planting season as the farm diesel demand backdrop. - California at **$7.222/gal** (down 1%, 46% above its 5-year median) anchors the West Coast (PADD 5), which as a whole lands at $6.524/gal, off 1% and 44% above its 5-year median. - Gulf Coast (PADD 3), **$5.122/gal**, down 1%: the low-cost anchor of the map, 45% above its own 5-year median. - West-vs-Gulf gap at **140.2 cents/gal**: the West Coast (PADD 5) at $6.524/gal over the Gulf Coast (PADD 3) at $5.122/gal, a standing structural spread. Gulf Coast ULSD spot (EIA daily, untaxed bulk wholesale) settled at **$3.916/gal** on May 18. New York Harbor ULSD spot settled at **$4.151/gal** on the same date. The US retail pump sits **$1.680/gal** over Gulf Coast spot. That spread includes fuel taxes and the full retail distribution layer, making it a hub-to-pump proxy rather than a station margin. --- Canonical URL: https://mondaydiesel.com/issues/2026-05-18