About & methodology
Exact sources, update cadence, and what this site will not do
What this site is
Weekly Diesel republishes the U.S. Energy Information Administration's weekly retail on-highway diesel price - the number freight contracts call “the DOE index” - for the U.S. average and all 10 EIA regions, with history to 1994, free CSVs, and fuel-surcharge math. It exists so that owner-operators, dispatchers, and brokers can check the week's number and their lane's surcharge in one place.
Sources
Primary: USDA AgTransport public mirror of the EIA series
(Socrata dataset x88w-atzp,
“Weekly On-Highway Diesel Fuel Prices”):
https://agtransport.usda.gov/Fuel/Weekly-On-Highway-Diesel-Fuel-Prices/x88w-atzp
API endpoint queried each build:
https://agtransport.usda.gov/resource/x88w-atzp.json
Origin of the data: EIA's weekly on-highway diesel price survey (Form EIA-888), published at https://www.eia.gov/petroleum/gasdiesel/ (methodology: https://www.eia.gov/petroleum/gasdiesel/diesel_proc-methods.php). EIA surveys a sample of retail diesel outlets - roughly 590 truck stops and service stations - as of 8:00 a.m. local time each Monday and publishes volume-weighted average prices in dollars per gallon, all taxes included. U.S. government data, public domain.
Gasoline (for the diesel vs gas page only): EIA's weekly U.S. regular-gasoline average, fetched from the Federal Reserve Bank of St. Louis FRED mirror (series GASREGW, fred.stlouisfed.org/series/GASREGW), which republishes the same EIA weekly survey.
Update cadence & staleness guard
Stations are surveyed each Monday; EIA releases the averages the next day, Tuesday around 10 a.m. ET - or Wednesday when Monday is a federal holiday (exact dates on the release schedule). The published week is always labeled by its survey Monday. This site rebuilds on each release. Every build cross-checks the mirror's latest week and U.S. price against EIA's own release page; the build fails rather than publish if the mirror lags the current EIA release by more than 8 days (more than one missed release), if the same-week prices disagree, or - when the EIA page is unreachable - if the mirror's latest week is more than 14 days old. On release day the mirror is normally one release behind, because it ingests EIA's file a day or more later; when that happens every dated page carries a notice naming both weeks and EIA's own national price, and the regional numbers update on the next build. So a number you see here is never silently stale. Latest build cross-check: EIA release “September 1, 2026”, week of , U.S. price $5.599 - matched the mirror exactly.
Method notes
Week-over-week change compares consecutive survey weeks. Year-over-year compares the closest survey week to 364 days earlier. Annual averages are simple means of the weekly readings (partial years marked). Regional series start later than the U.S. series where EIA introduced the split (PADD 1A/1B/1C in 1997, West Coast less California in 2011); California weekly data begins 1995. Nothing is interpolated or seasonally adjusted.
EIA redesigned the survey sample and estimation methodology effective the June 13, 2022 release; comparisons that span that date reflect both market and methodology changes. EIA publishes weekly retail diesel prices for the U.S. average, nine census/PADD regions, and exactly one state - California. There is no official weekly per-state diesel series for the other 49 states; sites showing one are estimating from other data.
What this site does not do
No forecasts, no buy/sell or rate advice, no invented statistics. The fuel-surcharge calculator and matrix are reference math from the published index - your contract's base price and divisor always govern. This site is independent and not affiliated with the U.S. Department of Energy, the EIA, or the USDA.
Contact
contact@weeklydiesel.com - corrections welcome and fixed fast.