Weekly Outlook
Australian Petrol Price
Market Pulse
Friday 25 September 2026 · Unleaded 91 and diesel · Based on oil markets, AUD/USD, and price cycle analysis
Produced automatically from PetrolPulse's live pricing data and forecast model — how our forecasts work. Methodology by Mark Schreuder · Data as of 25 September 2026
This week at a glance
Wholesale import costs lifted 6.0% over the past week to an estimated 170.2c/L — the input that flows through to pump prices over the following one to two weeks.
Wholesale market signals
Brent Crude
US$107.03
per barrel
Singapore MOGAS tracks Brent with ~1 week lag
AUD/USD
0.7015
exchange rate
A lower AUD raises imported fuel costs
Import Parity
170.2
cents per litre
Estimated wholesale cost before excise and GST
What this means for pump prices
Brent crude climbed 8.3% over the past week to US$107.03 per barrel, while the Australian dollar weakened 1.6% against the US dollar, lifting the local cost of imported fuel. These are the two inputs that, together with refining and shipping margins, determine the wholesale cost of fuel landed at Australian terminals.
The four-week outlook is broadly stable. Prices remain elevated — global supply costs are higher than usual Petrol import costs are currently around 23% above where they were six weeks ago, driven by global supply disruptions. While costs have stabilised in the short term, the price floor has risen — expect to pay more than historical averages for the foreseeable future. Short-term cycle swings still apply, but each peak and trough will be higher than what was normal before the disruption.
Historically, moves in import parity take about 10-14 days to show up at the bowser. With wholesale increases this week, you can expect the pressure to filter through to pump prices over the next two weeks — earlier in metros that follow a tight price cycle, later in regional markets where retailers smooth changes out.
City-by-city cycle outlook
Where each capital sits in its local discounting cycle right now, and what our model is telling drivers to do this week.
Shared signal — Sydney, Canberra, Hobart, Darwin
Import costs have dropped 6% in 2 weeks. The AUD has weakened 1.6%. Prices should ease as lower wholesale costs flow through to the pump. Fill up when you need to.
Sydney
Cycle position unclearYou have timeMelbourne
Cycle position unclearFill when you need toNo clear timing signal right now. Fill up when you need to.
Brisbane
Cycle position unclearYou have timeWorth waiting. The AUD has weakened 1.6%. Import costs have dropped 6% in 2 weeks. The upcoming cycle low (in ~2 days) should be noticeably cheaper as lower wholesale costs flow through to the pump.
Perth
Near trough — cycle lowYou have timePrices here follow a strong weekly pattern — Tuesday is usually cheapest, about 11¢/L below the week's peak. Worth waiting ~4 days for the weekly low.
Adelaide
Cycle position unclearFill when you need toNo clear timing signal right now. Fill up when you need to.
Canberra
Cycle position unclearYou have timeHobart
Cycle position unclearYou have timeDarwin
Cycle position unclearYou have timeLooking ahead
Perth is on the falling leg, which is when local prices typically reach their lowest before the cycle resets.
If your tank can wait, the next predicted price low is approaching in Sydney (around 0 days away from the next trough), Brisbane (around 2 days away from the next trough), Perth (around 4 days away from the next trough).
Common questions
When will petrol prices go down in Australia?
There are two separate answers, and they work on different clocks. Week to week, the biggest driver is your city's own discount cycle: prices climb quickly after a trough, then grind down over days or weeks until the next hike. Over months, the floor and ceiling of that cycle are set by the international refined petrol price (Singapore MOGAS 95) and the AUD/USD exchange rate, because Australia imports most of its refined fuel. So the next cheap day is a cycle question, and whether that cheap day is cheaper than last month's is a wholesale question. The city outlook above tracks the second; your city page tracks the first.
Will petrol prices go up or down this week?
It depends on where your city sits in its cycle right now, which is why there is no single national answer in any given week. Capitals run cycles of different lengths and can be at opposite ends of them on the same day, and cycle timing has been less regular since early 2026. The per-city outlook above gives the current directional call for each capital; the city pages carry the day-level fill-up recommendation.
How far ahead can petrol prices be forecast?
Roughly a few weeks, and confidence falls off sharply with distance. The wholesale inputs are genuinely forward-looking — Singapore MOGAS moves through to Australian pump prices over about one to three weeks, so a wholesale move today is largely knowable in advance. Cycle timing is the harder half: the depth of the next trough is more predictable than its exact date. PetrolPulse publishes its full tested record, including the market conditions where the model is weakest, rather than a single headline accuracy number.
Why do petrol prices keep changing?
Four things stack, in rough order of size. The international refined petrol price, set in Asian wholesale markets rather than in Australia. The AUD/USD exchange rate, because that fuel is bought in US dollars. Federal fuel excise plus GST, which is fixed between indexation dates. And the retailer's own margin, which is what produces the sawtooth discount cycle you see week to week. Only the last two are set in Australia, and the retail margin is the smallest share of what you pay — but it is the part that moves fastest.
Past updates
How this update is generated
Each day at 6:00am AEST, PetrolPulse fetches the latest Brent crude spot price and AUD/USD exchange rate. These are combined using the standard Singapore MOPS import parity formula to estimate the current wholesale cost of fuel delivered to Australian terminals.
Capital city averages are computed from live station-level data within a metro radius of each capital — not state-wide aggregates — so regional outliers don't skew the headline number. Comparisons against 7 and 30 days prior show whether each city is trending up or down, separate from the wholesale signal.
The city-by-city cycle outlook combines local cycle-position analysis with the forward-looking macro signals above. When import parity moves significantly relative to current retail prices and the recent margin, the directional call updates automatically.