If Australia introduced petrol rationing in response to Iran, how would it work and which sectors would be impacted?

Australia has not had petrol rationing since 1979. The last time it did, the mechanism was simple: a ration book, enough fuel for approximately 32km of driving per week, and a queue. Nearly five decades later, the mechanism has been updated, but the underlying problem, namely our structural dependence on imported refined fuel, has not.

The Strait of Hormuz crisis that began in late February 2026 has brought that problem into view with unusual clarity, and rationing, whilst not yet enacted, now sits explicitly within government contingency planning. Whilst this would be an emergency policy response, it is not as if there is nothing but past precedent to base such a policy on.

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How Petrol Rationing Could Work, and What Would Trigger It

The legal framework for fuel rationing in Australia sits inside the Liquid Fuel Emergency Act 1984, a piece of legislation updated most recently in 2019. Under the Act, the federal government can declare a liquid fuel emergency, which activates a coordinated response that includes purchase limits, price controls, and priority allocation to essential services. The National Liquid Fuel Emergency Plan, an agreement that came out of COAG in 2006 and was revised during COVID-19, provides the operational detail: state and territory governments hold powers over retail distribution, whilst the Commonwealth coordinates allocation at the wholesale level.

The specific rationing mechanism currently on the table is a $40 per transaction cap at the bowser. At current prices of around $2.20 per litre for unleaded, that would limit a fill to roughly 18 litres, about a third of a typical tank. It is a blunt instrument – its primary purpose is to suppress panic buying rather than to allocate scarce fuel strategically. The government has been explicit that formal rationing has not been triggered and that reserves remain above the threshold that would compel it.

As of late March 2026, Energy Minister Chris Bowen has confirmed approximately 38 days of petrol supply and 30 days each of diesel and jet fuel. The International Energy Agency’s mandatory minimum is 90 days. Australia has not met that benchmark since 2012 and has no realistic prospect of doing so in the near term.

The trigger for the Act is not a fixed number of days of supply. It is a ministerial judgement call, informed by import shipment flows, reserve drawdown rates, and the distribution of supply across the domestic network. Six of approximately 81 monthly inbound tankers have been cancelled or deferred for April. That is significant but not yet critical at scale, although its impact is felt acutely in regional and remote communities, which sit at the end of every supply chain and are effectively rationed by price and availability before any formal declaration is made.

The Sectors That Would Be Hit First and Hardest If Petrol Rationing Happened

If enacted, formal rationing would not distribute its costs evenly. Three sectors face disproportionate exposure.

Agriculture is the most immediate concern. Farming is diesel-dependent at every stage: cultivation, harvest, irrigation pumping, cold storage, and freight. The National Farmers’ Federation has warned that food price increases of up to 50 per cent are plausible if supply constraints persist. Unlike urban commuters who can reduce discretionary driving, farmers face operational minimums. The reality is, crops cannot wait for supply chains to normalise. So investors in companies in the fertiliser space, in general agriculture players or those specialising in specific commodities could be concerned.

Freight and logistics is the second pressure point. Bad news for companies like Qube (ASX:QUB), Freightways (ASX:FRW), Wiseway (ASX:WWG), Move Logistics (ASX:MOV) and perhaps even WiseTech (ASX:WTC). Diesel powers the trucks that carry almost every consumer good in Australia. Road freight accounts for the large majority of domestic cargo movement and has no short-term substitute. A $40 transaction cap does not directly address commercial vehicle fuelling. Whilst the government has signalled that essential services and freight operators would receive priority allocation, a sustained supply squeeze will raise costs across the entire supply chain regardless of what exemptions exist on paper.

The mining and resources sector is third on this list. Remote mine sites typically hold weeks of diesel inventory as a matter of operational necessity, but those buffers are not unlimited, and resupply under rationing conditions becomes logistically complex. The upstream cost impact flows directly to the cost base of producers whose output underpins significant ASX index weight.

Aviation sits in a distinct category. Jet fuel reserves are at 29 to 30 days, the tightest of the three main fuel classes. Airlines (such as Qantas (ASX:QAN), Virgin Australia (ASX:VGN) and Alliance Aviation (ASX:AQZ)) operate under long-term supply contracts with priority treatment in any emergency allocation framework, but elevated jet fuel costs compress margins immediately, and any allocation uncertainty creates operational risk for regional routes that have thinner margins and less scheduling flexibility.

Ampol: A Company On Both Sides of the Ledger

No publicly listed Australian company sits in a more structurally interesting position than Ampol (ASX:ALD) during this crisis. It is simultaneously a direct beneficiary of the supply shock and an entity whose long-term business model is under active government-directed pressure to change.

Ampol operates the Lytton refinery near Brisbane, which is one of only two operational refineries left in Australia, alongside Viva Energy’s Geelong facility. Together, they produce roughly 18 to 20 per cent of Australia’s liquid fuel demand. The remaining 80 per cent arrives as refined product from South Korean, Singaporean, Malaysian, and Chinese refineries, which themselves draw heavily on Middle Eastern crude transiting Hormuz.

The crisis has materially improved Ampol’s near-term earnings profile in several respects. First, the government temporarily amended fuel quality standards in March to allow petrol with a sulphur content of up to 50 parts per million, ten times the standard that had applied since December 2025. This is significant because Lytton produces higher-sulphur fuel that would previously have been exported for blending. Under the waiver, that fuel can now be sold directly into the Australian domestic market, adding 80 to 100 million litres per month to domestic supply. Ampol has committed to prioritising regional shortage areas and the wholesale spot market.

Second, the government has raised the support collar under the Fuel Security Services Payment from 6.4 to 10.0 cents per litre and made favourable adjustments to the margin calculation. The FSSP is the safety net that keeps Lytton commercially viable when refining margins collapse. A higher collar reduces Ampol’s earnings volatility in downturns, though the cap remains at 1.8 cents per litre.

Third, Ampol has deferred scheduled turnaround and inspection maintenance at Lytton from early June to August 2026. By keeping the refinery running at full capacity through the winter months, Ampol adds approximately 300 million litres of petrol, diesel, and jet fuel to domestic supply at a moment when prices are elevated and demand for locally produced fuel is acute. Critically, Lytton processes light sweet crude, not the Middle Eastern sour grades disrupted by the Hormuz closure, so Ampol’s crude sourcing has been relatively insulated from the specific supply disruption affecting importers.

Investors are Excited, but Are They Aware of the Risks?

The share price reflects all of this. Ampol has risen approximately 35% over the past 12 months, against 7% for the ASX 200. Ampol also produces or imports around 40% of Australia’s total oil product demand, giving it significant pricing power and distribution reach in a constrained market.

The risks run in the other direction, however. The government’s decision to temporarily roll back fuel standards may be commercially helpful to Ampol in the short term, but it exposes a structural problem that the Phase 2 Fuel Security Services Payment review is expected to address. Lytton’s output has historically been too high in sulphur to meet Australia’s retail standards, and the temporary waiver is not a long-term solution.

Ampol has acknowledged it missed its 2025 greenhouse gas emissions targets at Lytton, triggering a penalty on its sustainability-linked bonds. And the pending acquisition of EG Australia, which would materially expand Ampol’s retail network, awaits an ACCC determination due in June 2026, a regulatory process that becomes more politically loaded, not less, in a supply crisis where the competitive dynamics of fuel retailing are under public scrutiny.

What the Rationing Conversation Actually Reveals

Formal rationing is a policy instrument for managing supply that is already insufficient. Whether or not the $40 cap is ever deployed, the more durable questions are: First, how Australia closes the structural gap between its 36-day reality and the IEA’s 90-day standard; and second, who bears that cost?

For investors, the calculus is not simply about which sectors suffer when supply is constrained. It is about which companies are positioned at the chokepoints of a system that is now being redesigned in real time under emergency conditions. Ampol is one of those chokepoints. What the government does next, on reserve mandates, refinery support, fuel standards, and the EG acquisition, will determine whether Ampol’s current tailwind becomes a structural advantage or a transitional windfall.