Australia's Diesel Price Risk If the US Blocks Exports
Australian diesel could climb beyond $3 a litre if Donald Trump halts US diesel exports during negotiations with Iran, assessments published on 24 September 2026 warned. The Guardian
The broader context here is a clash between US domestic politics and a strained global market for distillate, the group of fuels that includes diesel. For Australia, the risk is higher prices spreading through world trade, not a direct loss of American barrels.
Prices already climbing
Fuel costs in late September reached levels not seen since early April. Prices rose nearly 40 cents per litre since the start of September. On 24 September, Canberra recorded diesel at 298.7 cents per litre and unleaded petrol at 250 cents per litre, the highest among Australian capital cities. The national diesel average was $2.74 per litre in the week before late September, while some local prices nudged above $3 a litre in September.
Oil and supply strains
Brent crude, the global benchmark for oil prices, held above US$100 per barrel for most of the fortnight before 24 September, its highest point since May 2026. Diesel exports from Gulf countries fell to a quarter of pre-war levels because conflict blocked tanker transit through the Strait of Hormuz and Bab al-Mandab, two narrow shipping lanes. Since the war began, the US raised supply, exporting over 1.5 million barrels of diesel per day, according to ANZ Bank analysts.
Why Washington is weighing a ban
The Trump administration was actively considering a ban on US diesel exports to lower prices at American service stations ahead of the November midterm elections. Trump said on 22 September 2026 that he backed a ban, endorsing a proposal pushed by Republican midterm candidates to lower fuel prices. The Guardian Treasury Secretary Scott Bessent said the administration was examining whether a ban would ease record-high diesel prices. The plan under preparation called for a 90-day ban on diesel exports to bring down energy prices. Politico
The idea divided the administration and drew resistance from the oil industry. Industry groups said banning US diesel exports would not make diesel cheaper. Top US energy officials warned it could raise fuel prices on the US coasts. US diesel prices were setting records because of the war in Iran. Futures for ultra-low-sulfur diesel, contracts tied to future delivery prices, fell around 5% after Politico reported the 90-day plan was being prepared. Reuters
Why Australia would still feel it
Direct US volumes make up a small share of Australian supply. Australia imported over 18,400 million litres of diesel from January to July 2026, with only 510.9 million litres from the US, most arriving in April. Diesel stockpiles fell to 31 days of supply in September 2026, down from 39 days in July 2026. The Albanese government temporarily lowered fuel excise, a tax charged on fuel, in March 2026 when diesel surpassed $3.10 a litre.
Looking at what analysts expect next, forecasts differ on severity. MST Financial analyst Saul Kavonic predicted Australia would have to ration diesel and face prices over $4 a litre within weeks of a US export ban. Dr Lurion De Mello of Macquarie University estimated diesel could surpass $3.10 a litre but was unlikely to reach $3.50 as long as Asian refiners continued to access oil.
The broader explanation here is pricing, not physical dependence. Diesel is fungible, meaning one barrel can replace another, like water moving between connected tanks. Removing more than 1.5 million barrels per day of US exports would tighten Atlantic balances and force buyers to bid more for replacement cargoes from Asia, the source Australia relies on for most imports. Thin cover explains why pump prices would rise even though US barrels were marginal through July.
Looking at what this means for policymakers, the March excise precedent matters. A temporary cut was used once diesel passed $3.10. Stock cover at 31 days leaves less buffer than in July if Gulf outages persist and Hormuz and Bab al-Mandab transits stay constrained. A 90-day ban in Washington might soften Midwest benchmarks while lifting coastal prices and inviting industry pushback, which is why futures sold off on the headline but officials cautioned about regional effects.
