Why Australia Pays What It Pays for Diesel
The real story in Australian diesel is not what happens at the service station. It is how cost and risk accumulate across six stages before a litre ever reaches the bowser.
As of 22 March 2026, Australia’s national average diesel price was 282 c/L. The Prime Minister went on television and told Australians to stop panic buying. Energy Minister Chris Bowen urged people to work from home. The IEA recommended cutting highway speed limits by 10 km/h. The ACCC took the unusual step of publicly announcing a formal enforcement investigation into Ampol, BP, Mobil, and Viva Energy—specifically their diesel allocation to independent regional distributors. Regional service stations had already run dry. The public debate focused on price gouging, the Middle East, and government inaction.
None of that debate produced a breakdown of where the 282 cents actually goes.
That number is worth following. Because the real story in Australian diesel is not what happens at the service station. It is how cost and risk accumulate across six stages before a litre ever reaches the bowser.
Stage 1: Crude
~109 c/L
The chain starts offshore, before any Australian decision has been made.
Australia produces about 220,000 barrels per day of crude oil and condensate. It exports more than 85% of that to refineries in South Korea, Japan, and Singapore. The reason is structural: Australian crude is light and sweet—premium-grade—and Asian mega-refineries pay a 5–10% price premium for it. Domestic refineries were built for heavier crude. So it has been consistently more profitable to export the premium product and import cheaper heavy crude for domestic processing.
The result: Australia starts the diesel supply chain as a pure price-taker. Global oil prices, denominated in US dollars, flow directly into the cost of every litre. The exchange rate alone adds several cents per litre when the Australian dollar weakens—approximately 3–4 c/L for every 10% move. In March 2026, as global crude prices rose sharply and the dollar weakened, the crude component roughly doubled from its normal ~36 c/L baseline. The week ending 22 March 2026, crude and feedstock costs account for approximately 109 c/L of the pump price.
Stage 2: Refining and Import Conversion
~60 c/L
Australia had eight operational refineries in 2005. It now has two: Lytton in Brisbane (Ampol) and Geelong (Viva Energy). Together, they cover only about 20–25% of domestic petrol and diesel demand. The rest—86% of diesel—is imported as finished product.
This distinction matters for reading the price stack. For domestically refined fuel, the relevant cost is the refiner margin: the spread between the cost of crude and the value of finished product. Under normal conditions, that margin is approximately 5–8 c/L, and it is the number the government subsidises through the Fuel Security Services Payment. But for 86% of diesel, the relevant cost is not a refiner margin at all—it is the full uplift from crude to delivered diesel product at the point of import, including the margin already taken by the overseas refinery.
That combined conversion block—domestic refining and imported finished product blended—runs to approximately 60 c/L in the March 2026 crisis period, elevated by the same Singapore price spike that was driving retail prices at the bowser.
Stage 3: Shipping and Storage
~9 c/L
Shipping, insurance, wharfage, and terminal handling add approximately 9 c/L in total (around 4 c/L for shipping, 5 c/L for storage and terminal handling). These are not the largest components of the price stack, but the storage figure carries a strategic weight disproportionate to its cost.
Australia holds approximately 26–29 days of petrol and diesel cover at any point. The International Energy Agency—the intergovernmental body Australia is a member of, established after the 1973 oil crisis—requires 90 days. Successive governments have described the cost of closing that gap (approximately A$20 billion in domestic storage infrastructure) as “economically unviable.” The cost of a 30-day supply disruption is estimated at A$20–50 billion in lost economic output. That comparison has not featured prominently in the policy debate.
Australia has systematised just-in-time fuel logistics and called it efficiency.
Stage 4: Wholesale and Distribution
~8 c/L
This is where international volatility converts into local prices.
Terminal Gate Prices—the published spot price at bulk distribution terminals—are recalculated daily based on a rolling average of Singapore Mogas prices for petrol, and Singapore Gasoil prices for diesel. Under normal conditions, the lag between a Singapore price movement and its appearance at the TGP is 7–10 days.
In March 2026, that lag effectively collapsed. As Singapore prices spiked in response to the Middle East conflict—which threatened crude supplies to the refineries that process 20% of the world’s seaborne oil—retailers repriced inventory they had purchased before the crisis at post-crisis prices. The ACCC was direct: “petrol retailers increased prices at the pump when they were selling fuel they had bought before the conflict at cheaper prices.” That difference, approximately 7 c/L, was margin extracted from pre-purchased inventory.
The logistics failure was less visible but more damaging for communities outside capital cities. According to the ACCC’s weekly monitoring update from 13 March 2026, regional independent distributors reported receiving approximately 10% of their normal daily allocations from major wholesalers, who prioritised their own retail networks. Fuel sat in bulk terminals in Sydney and Melbourne while rural Queensland and Western Australia ran dry.
Stage 5: Retail
~17.9 c/L
Retail is the most visible stage and the easiest to overstate.
The Gross Industry Retail Difference—the ACCC’s official measure of the retail margin—was 17.9 c/L in the December quarter of 2025. After wages, rent, electricity, and card fees, net fuel profit is approximately 3 c/L per litre. The station matters, but mostly as a convenience retail business that uses fuel as its traffic driver. Viva Energy’s On the Run chain generates more than 70% of its EBITDA from non-fuel. The fuel margin is not where the business is.
Stage 6: Tax
~78.2 c/L
The government’s take is a different story entirely.
Excise runs at 52.6 c/L from February 2026, a fixed amount per litre regardless of price. GST at 10% adds approximately 25.6 c/L at a 282 c/L pump price. Total tax: roughly 78.2 c/L—just under 28% of every litre sold. That figure rises in absolute dollar terms as the pump price rises: at 300 c/L, the GST component alone reaches 27.3 c/L.
The government takes more from each litre than the refiner, shipper, terminal operator, wholesaler, and retailer combined. The retailer keeps 3 c/L. The government keeps 78.2 c/L.
The number worth arguing about
At 282 c/L, the indicative price stack looks like this:
Crude/feedstock: ~109 c/L
Refining/import conversion: ~60 c/L
Shipping and storage: ~9 c/L
Wholesale and distribution: ~8 c/L
Retail gross margin: ~17.9 c/L (net fuel profit: ~3 c/L)
Tax (excise + GST): ~78.2 c/L
These upstream figures are indicative allocations built from benchmark pricing and published data, not separately audited margins for each stage. But they are directionally defensible—and they are the numbers missing from the public debate.
The public debate has asked whether retailers gouged. The ACCC found they extracted approximately 7 c/L in crisis margin from pre-purchased inventory. That is worth scrutinising. But it is a second-order question sitting on top of a first-order structural problem: a supply chain built to be entirely dependent on global markets, priced from a benchmark in Singapore, with less than 30 days of reserves and no sovereign buffer.
Most of the cost in Australian diesel accumulates before the fuel reaches the service station. Most of the risk does too.
The question of why that is—and whether it was a deliberate choice or an accidental one—is a different article that traces the four policy decisions, made over 40 years, that built this supply chain.
