How we get the number.

Every Sunday we pull EIA Weekly Retail Gasoline Prices — the same series the U.S. Department of Energy publishes — and pair them with EPA fuel-economy records (the fueleconomy.gov dataset). The whole pipeline is public, auditable, and cited inline on every page.

Where prices come from

EIA publishes weekly:

  • National average
  • 7 PADD regional averages (New England, Central Atlantic, Lower Atlantic, Midwest, Gulf Coast, Rocky Mountain, West Coast)
  • ~9 state averages: CA, CO, FL, MA, MN, NY, OH, TX, WA

States not in EIA's per-state series fall back to their PADD regional average. Crowdsourced reports will overlay state averages once enough come in.

Current snapshot: $3.83/gal national, week of 2026-06-29.

How the calc works

Fill-up cost = tank size (gal) × $/gallon. Miles per tank = tank × MPG. Annual cost = (miles/year ÷ MPG) × $/gallon.

Vehicle data: EPA Fuel Economy database (fueleconomy.gov), 30,299 variants from 1984 to current model year. Combined MPG = EPA-published city/highway average. Each variant — drivetrain, engine size, hybrid configuration — is preserved as a separate selectable option.

Tank capacity uses a 4-tier resolver: (1) year-range manufacturer spec for models with generational tank changes (Toyota Prius 3rd-gen 11.9 gal vs 4th-gen 11.3 gal vs 5th-gen 10.6 gal; Camry XV40 18.5 → XV80 13.2; F-150 12th-gen 26 → 13th-gen 23; Honda Civic/Accord by generation); (2) fuel-type-aware overrides for plug-in variants sharing one EPA model name (2012-2015 Prius Plug-in Hybrid 10.6 gal vs regular hybrid 11.9 gal; Hyundai Santa Fe/Tucson PHEV, Kia Sportage PHEV); (3) flat manufacturer spec for ~280 popular models (Mercedes E350, BMW 530i, Bentley Continental, Rolls-Royce Phantom etc.); (4) EPA vehicle class fallback for the long tail.

Fill-up cost shown is "empty to full" — tank capacity × price-per-gallon. Real-world fill is typically 70-85% of capacity, so the figure represents the maximum.

What we don't do

  • No GasBuddy / AAA scraping. Their data is theirs. We're independent — by design.
  • No station-level real-time pricing. Weekly granularity is sufficient for budget decisions; station-level requires a paid feed or scraping (legal exposure).
  • No price predictions. We report what's happening, not what might.

Attribution