Friday 11 September 2026 · By Mark Schreuder
Oil back above US$100: what it means for petrol prices
Oil has climbed back above US$100 a barrel as the Middle East conflict widens. The cost of landing petrol in Australia has jumped about 19 cents a litre in a fortnight, and only about a third of that has reached the pump so far.
Key points
- Brent crude closed above US$100 a barrel this week for the first time since May, after attacks on shipping and Saudi oil facilities
- Australia's wholesale petrol cost is up about 19 cents a litre in two weeks, but capital-city pump prices have risen only 3 to 10 cents so far
- PetrolPulse's model says fill up now in every capital except Perth, where the weekly cycle still bottoms on Tuesday
Petrol prices are heading up again, and the reason is on the other side of the world.
Brent crude settled above US$100 a barrel on Wednesday for the first time since May, after Iranian attacks on shipping near the Strait of Hormuz and Houthi strikes on Saudi oil facilities, Reuters reported.
By Thursday it was trading near US$108, up more than 20 per cent in two weeks. The Australian dollar has offered no cushion, sitting flat at about 72 US cents.
The cost of buying petrol overseas and shipping it here has already risen by about 19 cents a litre since late August. Pump prices have so far moved by only a third of that, so most of the increase is still on its way to the bowser.
What has reached the pump so far
Fuel prices in the capital cities have risen between 3 and 10 cents a litre over the past fortnight, according to PetrolPulse's daily averages.
- Canberra, Brisbane and Sydney: up 8 to 10 cents
- Hobart, Perth and Darwin: up 5 to 7 cents
- Melbourne and Adelaide: up about 3 cents
Unleaded now averages about 213 cents a litre across the eight capitals, and diesel about 259 cents.
That is roughly a third of the wholesale increase. The rest is still working its way through.
Why refined petrol matters more than crude
Australia does not import crude oil to make petrol. It imports petrol that has already been refined, priced off the Singapore market.
That Singapore price is rising faster than crude. The Australian Institute of Petroleum's latest weekly report puts it at just over 110 cents a litre, up 8 cents in a week, while crude rose about 5 cents.
The difference between the two, what refiners charge to turn oil into petrol, is now about 26 cents a litre. Its 12-month average is about 17 cents.
In other words, the war premium is being paid twice: once on the oil, and again on the refining.
How much further could petrol prices go?
Wholesale moves usually take one to two weeks to show up fully at the pump.
If oil stays above US$100 and the dollar holds near 72 US cents, capital-city unleaded could rise another 10 to 12 cents a litre over the next fortnight, taking averages into the low 220s.
That is not a prediction of where oil goes next. A ceasefire would unwind it as quickly as the attacks caused it. It is simply what today's wholesale price already implies.
PetrolPulse's four-week outlook currently reads "higher" for every capital. A price-cycle forecast alone would not see this coming: the cycle says nothing about a jump in the wholesale cost underneath it.
What should you do?
Seven of the eight capitals are on a "fill up now" call today. With import costs climbing, the cheapest day in the next week is most likely today.
Perth is the exception. Its weekly FuelWatch cycle still bottoms out on Tuesday, and the model says wait for it.
Check your city's forecast for the current call and find the cheapest station near you. In a rising market the gap between the cheapest and dearest station in the same suburb is often 10 cents or more.
The Market Pulse tracks the daily import cost, and how our calls have performed in past rising markets is published on the forecast accuracy page.
Common questions
Why are petrol prices going up in September 2026?
Because the wholesale cost of petrol has jumped. Brent crude rose above US$100 a barrel on 9 September as the Middle East conflict escalated, and the Singapore refined petrol benchmark that Australia actually imports rose even faster. PetrolPulse's import parity estimate is up 19¢/L in two weeks; pump prices have risen 3–10¢ so far depending on the city.
How much will petrol go up with oil at US$100 a barrel?
As of 10 September about 12¢/L of the September wholesale rise had not yet reached the pump. If crude holds near US$100 and the Australian dollar stays around 72 US cents, that flows through over one to two weeks, taking capital-city unleaded averages from around 213¢/L into the low-to-mid 220s. A fall in oil would reverse it.
Should I fill up now or wait?
In seven of the eight capitals PetrolPulse's model says fill up now: with import costs rising, the next week's cheapest day is most likely today. Perth is the exception because its weekly FuelWatch cycle still bottoms on Tuesday. Check the homepage for your city's current call, which updates daily.
How long does it take for oil prices to reach the pump in Australia?
Typically one to two weeks. Australian wholesale prices track a rolling average of the Singapore refined petrol benchmark, and retailers reprice as new, dearer fuel reaches their terminals. The July 2026 excise change, a comparable step in cost, took five to six days to plateau in most capitals.
Check your city's current forecast to see whether now is the right time to fill up.