Site methodology: where the numbers come from
Every price on this site comes from one dataset: the EIA Gasoline and Diesel Fuel Update, the weekly federal retail survey. No commercial feed, no estimate, no blend of sources. The current snapshot is the survey week of August 31, 2026, pulled 2026-09-06. [EIA · 31 Aug 2026]
The source
The U.S. Energy Information Administration collects retail prices from a panel of outlets on Monday morning and publishes the same afternoon ET. Prices are collected Monday morning and published the same Monday afternoon ET (Tuesday when Monday is a federal holiday). We read it through the EIA Open Data API v2, route petroleum/pri/gnd, and store the snapshot as a JSON file the site imports at build time. The national series are EMM_EPMR_PTE_NUS_DPG for regular gasoline and EMD_EPD2D_PTE_NUS_DPG for on-highway diesel; every state and district page shows the series id behind its own figure.
What the survey covers, and what it does not
For regular gasoline, EIA publishes a weekly retail price for the United States, the five PADDs, three PADD 1 sub-districts (New England, Central Atlantic, Lower Atlantic), West Coast less California, ten metro areas, and nine individual states: CA, CO, FL, MA, MN, NY, OH, TX, WA.
It publishes nothing for the other 42 jurisdictions. For on-highway diesel the coverage is narrower still: the United States, the districts, and California only.
How this site handles the gap
A state without its own series carries the figure for the EIA district it sits in. The page names the district, shows the series id, marks the row as regional rather than state, and repeats the caveat in the metadata and the FAQ schema. We do not interpolate, weight, model or borrow from another publisher to manufacture a state number. Where a state sits inside a district whose economics clearly do not describe it, Alaska and Hawaii inside PADD 5 being the obvious cases, the page says that too.
Two states inside the same district therefore show the same price. That is not a bug in the data pipeline. It is what the federal survey actually contains, and printing two different numbers there would mean inventing the difference.
How the figures are checked
The data file is built from the API, then verified against EIA's own published HTML tables, which are generated by a different EIA system: the summary tables at eia.gov/petroleum/gasdiesel and the per-area pages under eia.gov/dnav/pet. Seventeen values, national, district and state, across both fuels, are compared on every build. A mismatch fails the build rather than shipping.
Refresh cadence
Weekly, following the EIA release. The survey week shown at the top of every page is the reference period, not the date the page was rendered.
Licence
EIA data are U.S. Government works in the public domain. Public domain (U.S. Government work). https://www.eia.gov/about/copyrights_reuse.php
Data that is not EIA
- State excise rates: American Petroleum Institute motor fuel tax map and the Tax Foundation 2026 ranking. [API · 31 Aug 2026] [Tax Foundation · 31 Aug 2026] Reviewed quarterly.
- Federal excise: FHWA Highway Statistics. 18.4 cents per gallon gasoline including the 0.1 cent LUST levy, 24.4 cents per gallon diesel. Unchanged since 1 October 1993. [FHWA · 31 Aug 2026]
- Cost-stack shares: EIA Petroleum Marketing Monthly. These are national shares applied to a district or state price, and are labelled as estimates on the pages that use them.
What this site does not publish
Station-level prices. Intraday updates. A distinct daily price for all fifty states. Any figure we cannot point at a series id for.
How to cite
Cite EIA directly: EIA Gasoline and Diesel Fuel Update, week of August 31, 2026, series id as shown. A machine-readable export of the mapped table is at /data/.