21 April 2026
Media Release
New analysis from Fishbowl Inventory, conducted by Primara Research, examining Australian Institute of Petroleum terminal gate price data against national retail fuel prices, reveals that while petrol prices are trending toward recovery, diesel costs running 59% above pre-crisis levels and an expiring federal excise cut suggest Australians may have more cost pressure ahead than the bowser currently indicates.
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The Good News Has a Catch
Petrol wholesale costs have fallen 7.3% per week since the crisis peak. At that rate, prices are approximately three weeks from returning to normal, which would be genuine relief for millions of motorists absorbing the highest fuel costs in years.
But a little-known government deadline could extend that timeline. The temporary federal excise cut introduced during the crisis applies to both petrol and diesel. If it lapses without extension in July, the full excise is added back on, equivalent to wiping out approximately two further weeks of price reductions at the current rate of decline. Three weeks of relief may be closer to five, and only if wholesale costs continue falling without disruption.
Diesel's Real Threat Is Not the Price, It's Where the Cost Is Going
While petrol is 22% above pre-crisis wholesale levels and recovering, diesel remains at 59%, and the gap between those two numbers tells the more consequential story.
On 9 April, with retail margins at their lowest point of the crisis, modelling shows diesel could have reached $3.90 a litre had normal margins and the full fuel excise applied simultaneously. That it did not reflects the extraordinary compression retailers absorbed, with margins collapsing to just 1.7% that week, meaning 83 cents of every dollar of normal profit was wiped out in a single week to keep prices from that peak.
Margins have partially recovered to 8.5%, but across the full eight weeks of the crisis, diesel margins averaged just 6% against a normal benchmark of 9.8%. That 3.8 percentage point gap has been absorbed by retailers rather than passed on. Diesel powers every truck, freight run and warehouse delivery moving food and goods across Australia, meaning those deferred costs do not disappear, they move into freight rates, logistics contracts and ultimately shelf prices.
What It Could Mean
If wholesale diesel costs remain elevated and margins continue recovering toward normal, that pressure could compound further when the July excise return lands on diesel simultaneously, creating an inflation risk for goods prices rather than just fuel.
"The diesel numbers are the ones businesses managing logistics and supply chains should be watching. Retailers have been running margins nearly four points below normal for eight weeks, with wholesale diesel still 59% above pre-crisis. When the July excise lands on top, goods prices become the most probable destination for costs that have so far been absorbed, not passed on," said Simon Jupe, Managing Director APAC at Fishbowl Inventory.
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Data in this release is sourced from the Australian Institute of Petroleum's terminal gate price (TGP) and average national retail fuel price data, reported on a weekly basis and current as at 20 April 2026. Analysis was completed by Primara Research for Fishbowl. As AIP prices update daily, figures displayed on their website may differ from those used in this analysis. Margins represent the difference between the TGP and the national average retail price, and reflect the combined margin across the retailer and distributor, including transport costs. Margins will therefore vary by individual retailer and location.