An independent guide to the price at the pumpData release · 30 September 2026
Home / Western Australia (AU) | Fuel price evidence
The evidence behind the price
Western Australia: what changed?
Dated inputs, measured movements and the limits of each comparison.
Why prices changed
Gasoline / petrol
+0.080 AUD/L (+3.535%)
The gasoline price moved from 2.263 on 2026-09-20 to 2.343 on 2026-09-27. The chart reconciles the measured change using the site’s accounting model.
Crude benchmark movement
-0.042
Exchange-rate movement
+0.013
Refining & distribution residual
+0.102
Taxes
+0.007
Rounding / unallocated remainder
-0.000
Contribution values
Estimated accounting contributions, AUD/L
Component
Change
Crude benchmark movement
-0.042
Exchange-rate movement
+0.013
Refining & distribution residual
+0.102
Taxes
+0.007
Rounding / unallocated remainder
-0.000
Left: decrease. Right: increase. Oil is valued at the earlier FX rate; currency movement uses the later oil price. The downstream residual includes unmeasured costs and timing, not just margins. Taxes can change with prices without a policy change. This is accounting, not proof of causation.
Diesel
+0.134 AUD/L (+5.007%)
The diesel price moved from 2.676 on 2026-09-20 to 2.810 on 2026-09-27. The chart reconciles the measured change using the site’s accounting model.
Crude benchmark movement
-0.042
Exchange-rate movement
+0.013
Refining & distribution residual
+0.151
Taxes
+0.012
Rounding / unallocated remainder
+0.000
Contribution values
Estimated accounting contributions, AUD/L
Component
Change
Crude benchmark movement
-0.042
Exchange-rate movement
+0.013
Refining & distribution residual
+0.151
Taxes
+0.012
Rounding / unallocated remainder
+0.000
Left: decrease. Right: increase. Oil is valued at the earlier FX rate; currency movement uses the later oil price. The downstream residual includes unmeasured costs and timing, not just margins. Taxes can change with prices without a policy change. This is accounting, not proof of causation.
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.
Relative movements, not a breakdown of pump costs. Crude is a proxy, not wholesale fuel.Chart data and publishers (4 observations)
Date
Pump, AUD/L
Crude proxy, local / L
Publisher
2026-09-06
2.054
0.893
Australian Institute of Petroleum
2026-09-13
2.113
1.035
Australian Institute of Petroleum
2026-09-20
2.263
1.057
Australian Institute of Petroleum
2026-09-27
2.343
1.028
Australian Institute of Petroleum
3 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.
Relative movements, not a breakdown of pump costs. Crude is a proxy, not wholesale fuel.Chart data and publishers (4 observations)
Date
Pump, AUD/L
Crude proxy, local / L
Publisher
2026-09-06
2.490
0.893
Australian Institute of Petroleum
2026-09-13
2.535
1.035
Australian Institute of Petroleum
2026-09-20
2.676
1.057
Australian Institute of Petroleum
2026-09-27
2.810
1.028
Australian Institute of Petroleum
3 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 / petrolNo curated policy events fall within the displayed price history.Chart data and publishers (4 observations)
Date
Pump, AUD/L
Publisher
2026-09-06
2.054
Australian Institute of Petroleum
2026-09-13
2.113
Australian Institute of Petroleum
2026-09-20
2.263
Australian Institute of Petroleum
2026-09-27
2.343
Australian Institute of Petroleum
2022-03-30
Australian fuel excise temporarily halved
Temporary measure from 30 March through 28 September 2022. A numeric household estimate is withheld until the applicable before and after rates are recorded.
A monetary impact is not estimated from the available verified rates.
DieselNo curated policy events fall within the displayed price history.Chart data and publishers (4 observations)
Date
Pump, AUD/L
Publisher
2026-09-06
2.490
Australian Institute of Petroleum
2026-09-13
2.535
Australian Institute of Petroleum
2026-09-20
2.676
Australian Institute of Petroleum
2026-09-27
2.810
Australian Institute of Petroleum
2022-03-30
Australian fuel excise temporarily halved
Temporary measure from 30 March through 28 September 2022. A numeric household estimate is withheld until the applicable before and after rates are recorded.
A monetary impact is not estimated from the available verified rates.
Publisher: Australian Institute of Petroleum. Observation: 2026-09-27. Last successful publisher refresh: 2026-09-30 07:43:10 UTC. Observation ingestion: 2026-09-30 07:41:41 UTC.
Original value: 234.3 AUD cents/L. Display: 2.343000 AUD/L. Method: derived.
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.
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)
Observation
Price / L
Version
2026-09-30T07:44:54.843333Z
2026-09-27
2.343000 AUD
2a9af43396d9
2026-09-24T13:02:09Z
2026-09-20
2.263000 AUD
7d9786823756
2026-09-23T06:02:23Z
2026-09-20
2.263000 AUD
00d93fbf6cba
Diesel
Publisher: Australian Institute of Petroleum. Observation: 2026-09-27. Last successful publisher refresh: 2026-09-30 07:43:10 UTC. Observation ingestion: 2026-09-30 07:42:53 UTC.
Original value: 281 AUD cents/L. Display: 2.810000 AUD/L. Method: derived.
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.
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.