What Gas Costs
and Why
An independent guide to the price at the pumpData release · 30 September 2026
Home / Iowa (US) | Fuel price evidence

The evidence behind the price

Iowa: what changed?

Dated inputs, measured movements and the limits of each comparison.

Why prices changed

Gasoline / petrol

A matching publisher and a 6–10 day comparison are required.

Diesel

A matching publisher and a 6–10 day comparison are required.

Reporting around these observation dates

Source headlines provide context. Their presence does not establish what caused the price movement.

No matching source reports are available for this observation interval.

Oil fell. Did the pump follow?

Gasoline / petrol

Does local crude movement line up more closely with pump changes in the same week or later? This compares weekly changes at delays of 0 to 8 weeks over up to five years, using the latest continuous publisher and currency segment.

Pump price and local-currency crude, indexed to 1002026-09-10 to 2026-09-30. Navy is pump price; teal is crude. A data table follows.02855831102026-09-102026-09-30Pump price (navy) · Crude in local currency (teal) · First paired date = 100
Relative movements, not a breakdown of pump costs. Crude is a proxy, not wholesale fuel.
Chart data and publishers (3 observations)
DatePump, USD/LCrude proxy, local / LPublisher
2026-09-101.0940.651AAA state gas price averages
2026-09-141.0890.644AAA state gas price averages
2026-09-301.1170.606AAA state gas price averages

0 compatible weekly changes; at least 52 are required for lag analysis.

At least 52 compatible weekly changes are needed; each correlation needs 12 pairs and variation in both series. Joins allow one day of reporting-date variation. Missing weeks are not filled. Each later pump change covers one week, not a cumulative response. Correlation does not measure a causal pass-through delay or prove that rises travel faster than falls. No forecast is implied. Benchmark and FX inputs are no more than 10 days old and never from a future date.

Diesel

Does local crude movement line up more closely with pump changes in the same week or later? This compares weekly changes at delays of 0 to 8 weeks over up to five years, using the latest continuous publisher and currency segment.

Pump price and local-currency crude, indexed to 1002026-09-10 to 2026-09-30. Navy is pump price; teal is crude. A data table follows.02958871162026-09-102026-09-30Pump price (navy) · Crude in local currency (teal) · First paired date = 100
Relative movements, not a breakdown of pump costs. Crude is a proxy, not wholesale fuel.
Chart data and publishers (3 observations)
DatePump, USD/LCrude proxy, local / LPublisher
2026-09-101.5120.651AAA state gas price averages
2026-09-141.6010.644AAA state gas price averages
2026-09-301.6200.606AAA state gas price averages

0 compatible weekly changes; at least 52 are required for lag analysis.

At least 52 compatible weekly changes are needed; each correlation needs 12 pairs and variation in both series. Joins allow one day of reporting-date variation. Missing weeks are not filled. Each later pump change covers one week, not a cumulative response. Correlation does not measure a causal pass-through delay or prove that rises travel faster than falls. No forecast is implied. Benchmark and FX inputs are no more than 10 days old and never from a future date.

Policy dates alongside prices

Gasoline / petrol
USD per litre, with policy event dates2026-09-10 to 2026-09-30. Dashed lines mark verified policy events; they do not establish causation. A data table follows.0.000.300.600.901.212026-09-102026-09-30AAA state gas price averages · USD/L
No curated policy events fall within the displayed price history.
Chart data and publishers (3 observations)
DatePump, USD/LPublisher
2026-09-101.094AAA state gas price averages
2026-09-141.089AAA state gas price averages
2026-09-301.117AAA state gas price averages

No legal policy events have been curated for this region yet. This is not evidence that policy has been unchanged.

Event coverage is selective. Source tax-rate snapshots are not automatically treated as legal changes. Upcoming recorded tax dates · All regional tax records

Diesel
USD per litre, with policy event dates2026-09-10 to 2026-09-30. Dashed lines mark verified policy events; they do not establish causation. A data table follows.0.000.440.871.311.752026-09-102026-09-30AAA state gas price averages · USD/L
No curated policy events fall within the displayed price history.
Chart data and publishers (3 observations)
DatePump, USD/LPublisher
2026-09-101.512AAA state gas price averages
2026-09-141.601AAA state gas price averages
2026-09-301.620AAA state gas price averages

No legal policy events have been curated for this region yet. This is not evidence that policy has been unchanged.

Event coverage is selective. Source tax-rate snapshots are not automatically treated as legal changes. Upcoming recorded tax dates · All regional tax records

Source receipts

Gasoline / petrol

Publisher: AAA state gas price averages. Observation: 2026-09-30. Last successful publisher refresh: 2026-09-30 07:39:46 UTC. Observation ingestion: 2026-09-30 07:39:46 UTC.

Original value: 4.2273 USD USD/gal. Display: 1.116735 USD/L. Method: derived.

Crude input
WTI 96.41 USD/barrel, 2026-09-22
Display currency FX
USD_USD 1, 2026-09-30
Source currency FX
USD_USD 1, 2026-09-30
Reuse terms
AAA Fuel Prices, all rights reserved. Publicly displayed state averages; retain attribution. Not EIA public-domain data.

Derived method: crude = USD/barrel / 158.987 * local currency/USD; yield factor 1.0; downstream = price - taxes - crude. Currency conversion uses display FX / source FX; US gallons convert at 3.785411784 L. Missing inputs are never zero. Benchmark availability alone does not imply a complete component breakdown. Full methodology.

Download receipts and calculation inputs · Historical observations

Publication and revision history (3 saved versions)

Tracking begins with this feature’s first export. A new observation is a publication; a changed value for the same observation date is a revision. This is our publication history, not a complete publisher revision archive. At most 30 versions per fuel are shown; the canonical database retains all recorded versions.

Recorded (UTC)ObservationPrice / LVersion
2026-09-30T07:44:55.600029Z2026-09-301.116735 USDedd591285f72
2026-09-29T13:02:15Z2026-09-141.089049 USD53633cb39eb5
2026-09-23T06:02:25Z2026-09-141.089049 USD7351ec377d29
Diesel

Publisher: AAA state gas price averages. Observation: 2026-09-30. Last successful publisher refresh: 2026-09-30 07:39:46 UTC. Observation ingestion: 2026-09-30 07:39:46 UTC.

Original value: 6.1326 USD USD/gal. Display: 1.620062 USD/L. Method: derived.

Crude input
WTI 96.41 USD/barrel, 2026-09-22
Display currency FX
USD_USD 1, 2026-09-30
Source currency FX
USD_USD 1, 2026-09-30
Reuse terms
AAA Fuel Prices, all rights reserved. Publicly displayed state averages; retain attribution. Not EIA public-domain data.

Derived method: crude = USD/barrel / 158.987 * local currency/USD; yield factor 1.0; downstream = price - taxes - crude. Currency conversion uses display FX / source FX; US gallons convert at 3.785411784 L. Missing inputs are never zero. Benchmark availability alone does not imply a complete component breakdown. Full methodology.

Download receipts and calculation inputs · Historical observations

Publication and revision history (3 saved versions)

Tracking begins with this feature’s first export. A new observation is a publication; a changed value for the same observation date is a revision. This is our publication history, not a complete publisher revision archive. At most 30 versions per fuel are shown; the canonical database retains all recorded versions.

Recorded (UTC)ObservationPrice / LVersion
2026-09-30T07:44:55.606622Z2026-09-301.620062 USD8185da732f9b
2026-09-29T13:02:15Z2026-09-141.600962 USD46e25082d712
2026-09-23T06:02:25Z2026-09-141.600962 USDfdd7de587b46

Iowa price overview · Embed this region’s chart