One Week of the Excise Cut: The Full Picture
Seven days after the excise was halved, petrol is at 111% pass-through nationally — every state except the NT has crossed 100%. Diesel has gone backwards, collapsing to just 32% pass-through as wholesale costs overwhelm the cut.
One week since the fuel excise was halved. Two very different stories.
Petrol: mission accomplished. The national U91 average has dropped 29.3 cents per litre from the day before the cut — from 259.0 to 229.7 c/L. That's 111.4% of the 26.3 cent excise reduction. On a 65-litre tank, that's $19.05 in savings. Seven of eight states have crossed full pass-through.
Diesel: going backwards. Diesel Combined has risen from 310.4 c/L on Day 4 to 315.8 c/L today. Pass-through has collapsed from 53% to just 32.3%. Standard diesel is barely 7 cents below where it was before the cut.
The petrol story — one week in
| Fuel | Before cut (c/L) | Day 1 (c/L) | Day 4 (c/L) | Day 7 (c/L) | Total drop | Pass-through |
|---|---|---|---|---|---|---|
| U91 | 259.0 | 242.0 | 232.3 | 229.7 | 29.3 | 111.4% |
| E10 | 254.5 | 234.5 | 225.4 | 223.5 | 31.0 | 117.9% |
| U95 | 274.0 | 254.9 | 245.4 | 243.5 | 30.5 | 116.0% |
| U98 | 282.6 | 264.4 | 254.7 | 252.4 | 30.2 | 114.8% |
Every grade is well above 100% pass-through. E10 continues to lead at 117.9%, consistent with what we've seen since Day 2.
The excise cut is 26.3 c/L ex-GST, but because fuel carries 10% GST, the full retail impact of halving the excise is actually 28.93 c/L. The U91 drop of 29.3 c/L essentially matches this GST-inclusive figure — the excise cut has been passed through almost exactly as the economics would predict, with a small additional boost from natural price cycle movements.
The progression tells the story of how quickly the market adjusted:
- Day 1: 65% — two-thirds at the pump overnight
- Day 4: 101.5% — full pass-through crossed
- Day 7: 111.4% — settled above the line with cycle effects
From Day 4 to Day 7, U91 dropped a further 2.6 c/L. The pace has slowed as expected — the excise cut itself is now fully absorbed, and remaining movement is natural cycle activity.
The diesel problem
This is the headline that should concern the ACCC.
| Fuel | Before cut (c/L) | Day 1 (c/L) | Day 4 (c/L) | Day 7 (c/L) | Total drop | Pass-through |
|---|---|---|---|---|---|---|
| Diesel | 323.6 | 312.2 | 312.2 | 316.4 | 7.2 | 27.4% |
| Premium Diesel | 325.1 | 310.1 | 308.5 | 315.1 | 10.0 | 38.0% |
| Diesel Combined | 324.3 | 311.2 | 310.4 | 315.8 | 8.5 | 32.3% |
Standard diesel has risen 4.2 c/L since Day 4. It's now just 7.2 c/L below the pre-cut price. That's 27.4% pass-through — barely more than a quarter of the cut has reached diesel pumps after a full week.
Premium diesel has risen 6.6 c/L since Day 4. The premium diesel story has reversed entirely — from 63.1% pass-through on Day 4 to just 38.0% today.
Diesel Combined tells the full story: on Day 4, pass-through was 52.9%. Today it's 32.3%. It hasn't just stalled — it's actively reversing.
For a diesel driver filling a 65-litre tank, the excise cut should be saving them $17.10. They're getting $5.53. That's $11.57 missing every fill.
The problem is global wholesale diesel costs, which have risen sharply through the first week of April. The excise cut is pulling prices down, but wholesale costs are pushing them up harder. This isn't necessarily retailers pocketing the excise cut — it's the global diesel market overwhelming the domestic policy lever.
That said, the ACCC's enhanced $100 million penalty regime means retailers can't use wholesale costs as cover to widen margins. The distinction matters: legitimate cost pass-through vs opportunistic margin expansion. The ACCC's ongoing investigations into the major retailers should be looking closely at diesel margins this week.
State by state — U91
| State | Before cut (c/L) | Day 1 (c/L) | Day 4 (c/L) | Day 7 (c/L) | Total drop (c/L) | Pass-through |
|---|---|---|---|---|---|---|
| ACT | 258.0 | 234.5 | 224.7 | 224.2 | 33.8 | 128.5% |
| SA | 262.0 | 239.2 | 231.8 | 230.8 | 31.2 | 118.6% |
| VIC | 258.8 | 239.8 | 231.3 | 228.0 | 30.8 | 117.1% |
| TAS | 259.4 | 237.8 | 232.2 | 230.4 | 29.0 | 110.3% |
| WA | 255.6 | 249.3 | 229.6 | 226.9 | 28.7 | 109.1% |
| NSW | 258.9 | 243.1 | 233.3 | 230.2 | 28.7 | 109.1% |
| QLD | 259.2 | 240.7 | 233.0 | 230.6 | 28.6 | 108.7% |
| NT | 269.6 | 253.3 | 249.3 | 249.3 | 20.3 | 77.2% |
Seven of eight states and territories are above 108% pass-through. The excise cut has unambiguously reached petrol pumps across the country.
The leaders
ACT continues to lead at 128.5% — a 33.8 cent drop, or $21.97 less on a 65-litre tank compared to a week ago. The ACT's small, competitive market has responded faster and further than anywhere else.
South Australia holds second at 118.6%. SA has been consistently above 85% since Day 1 — steady pass-through with no wobbles.
Victoria has strengthened to 117.1% from 104.6% on Day 4. VIC's regulated daily price caps appear to be working as intended, ensuring the excise cut reaches consumers quickly and completely.
The middle pack
Tasmania (110.3%), Western Australia (109.1%), NSW (109.1%), and Queensland (108.7%) are all comfortably above full pass-through. The spread between them is just 1.6 c/L — essentially identical performance.
NSW has crossed full pass-through from 97.3% on Day 4 to 109.1% across 1,943 stations — the largest sample in the country.
WA was the slowest starter (24% on Day 1, due to FuelWatch's next-day pricing cycle) but has caught up to 109.1% — a remarkable recovery.
The outlier
Northern Territory is at 77.2% and has been stuck at 249.3 c/L since Day 3. With just 84 stations — many in remote communities with limited competitive pressure — the NT was always going to be the slowest to adjust. But four days of zero movement warrants scrutiny.
The 32c/L question
States and territories agreed to fund a further 5.7c/L excise cut on Day 2, bringing the total reduction to 32c/L. One week later, there's still no visible evidence of that additional cut in pump prices.
If the full 32c/L (inc GST: 35.2 c/L) had been passed through, the national U91 average would be around 223.8 c/L. It's currently at 229.7 — about 6 cents away. This gap roughly matches the missing 5.7c/L additional cut.
All pass-through figures in this series remain measured against the original 26.3c/L cut. If the additional 5.7c/L begins reaching pumps, we'll shift to measuring against the full 32c/L benchmark.
The week in context
In 2022, the ACCC found that petrol prices dropped 25 to 35 cents per litre within the first week of the excise cut. This time, the national U91 average has dropped 29.3 c/L in seven days — right in the middle of that range.
The petrol story is a success by any reasonable measure. The diesel story is a concern that warrants regulatory attention. Australian diesel drivers are effectively subsidising global wholesale cost increases, with the excise cut being absorbed before it reaches the pump.
What happens next
- Day 14 (14 April) — two-week progress report
- Day 30 (1 May) — the monthly report card
The key questions for the next week:
- Does diesel pass-through stabilise or continue declining?
- Does the additional 5.7c/L cut start appearing at pumps?
- Does the NT begin to catch up?
Use BowserBuddy to find the cheapest fuel near you. Even with petrol well past full pass-through nationally, there's still a 20+ cent spread between the cheapest and dearest station in most areas.
How we calculated this
This analysis uses BowserBuddy's own price tracking data across all eight states and territories. For each station and fuel type, we take the latest known price as of end of day, then compute a station-count-weighted average at the state and national level. This captures the full market — every active station, not just those that changed prices on a given day.
Comparison period: All figures are compared to a full-market snapshot on March 31 (the last full day before the cut took effect). Day 1 and Day 4 figures are from our published daily analyses at those milestones.
Pass-through percentage: Calculated as the price drop divided by 26.3 c/L (the ex-GST excise cut). Pass-through above 100% is possible when the excise cut coincides with a natural price cycle decline, and because the GST-inclusive impact of the cut is actually 28.93 c/L. All figures in this post measure against the original 26.3c/L cut, not the expanded 32c/L.
Daylight saving: AEDT ended at 3am on 5 April 2026. All Day 7 data is on Australian Eastern Standard Time across all states and territories.
What's excluded: Closed stations, out-of-stock prices, suspected reporting errors, and prices outside reasonable bounds are all filtered before averaging. Prices older than 14 days are excluded as stale. For full details on our data quality approach, see the Data Transparency section on our prices dashboard.
Diesel Combined is a station-count-weighted blend of standard Diesel and Premium Diesel — reflecting the fact that most stations sell one or the other, and drivers take what's available.
Sample sizes: Today's national averages are based on approximately 6,850 U91 price reports and 8,760 diesel price reports across all eight states and territories.