Market Update
Tuesday 18 August 2026
Unleaded 91 and diesel · Brent crude, AUD/USD, capital pump prices, and city-by-city 4-week outlook
Produced automatically from PetrolPulse's live pricing data and forecast model — how our forecasts work. Methodology by Mark Schreuder · Data as of 18 August 2026
What moved this week
As of Tuesday 18 August 2026, the national average for Unleaded 91 across Australia's capital cities sits at 200.4c/L, down 3.3c on last week. Diesel averages 245.9c/L nationally, with the cheapest reported bowser at 225.5c/L. Wholesale import costs held steady 1.0% over the past week to an estimated 153.5c/L — the input that flows through to pump prices over the following one to two weeks.
Wholesale market signals
Brent Crude
US$91.00
per barrel
Singapore MOGAS tracks Brent with ~1 week lag
AUD/USD
0.7087
exchange rate
A lower AUD raises the cost of imported fuel
Import Parity
153.5
cents per litre
Estimated wholesale cost before excise and GST
What this means for pump prices
Brent crude climbed 2.1% over the past week to US$91.00 per barrel, while the Australian dollar held flat 0.3% against the US dollar. 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 leaning lower. Retail margins elevated — correction likely Petrol stations are earning 12c/L more than their historical average margin. This level of profitability tends to attract competition and compress prices over time — even if crude stays flat. Prices may ease in the coming weeks.
Import parity hasn't moved much this week, so any pump price changes you see at the bowser will be driven mainly by the local discounting cycle rather than the global signal.
Capital city pump prices
Average and cheapest reported pump prices in each capital on Tuesday 18 August 2026, with the change vs 7 and 30 days prior.
| City | U91 avg | U91 cheap |
|---|---|---|
| Sydney | 197.4c | 179.5c |
| Melbourne | 197.9c | 99.0c |
| Brisbane | 199.3c | 185.5c |
| Adelaide | 200.2c | 187.9c |
| Perth | 191.9c | 182.7c |
| Canberra | 200.6c | 189.7c |
| Hobart | 208.1c | 184.5c |
| Darwin | 208.0c | 197.5c |
Averages computed from stations within a metro radius of each capital. 7d and 30d deltas apply to the U91 average.
City-by-city cycle outlook
Where each capital sat in its local discounting cycle on Tuesday 18 August 2026, and what the model was telling drivers to do.
Shared signal — Sydney, Adelaide, Hobart
Even though the price cycle suggests waiting, import costs have risen 8% in two weeks. The next cycle low will likely be higher than recent lows. Filling up now locks in a better price than waiting.
Sydney
Falling — heading toward troughFill up nowMelbourne
Falling — heading toward troughFill when you need toNo clear timing signal right now. Fill up when you need to.
Brisbane
Falling — heading toward troughYou have timeA price low is expected in about 4 days — worth holding off if your tank allows.
Perth
Near trough — cycle lowFill up nowFill up now. Rising import costs (8% in 2 weeks) mean the next cycle low will be higher than recent lows. Prices at the pump are likely to stay elevated.
Adelaide
Near trough — cycle lowFill up nowCanberra
Falling — heading toward troughYou have timeNo sharp moves expected in the next few days — if your tank allows, there's no rush to fill up today.
Hobart
Falling — heading toward troughFill up nowDarwin
Falling — heading toward troughYou have timeNo sharp moves expected in the next few days — if your tank allows, there's no rush to fill up today.
Looking ahead
Sydney, Melbourne, Brisbane, Perth, Adelaide, Canberra, Hobart, Darwin are 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 Canberra (around 0 days away from the next trough), Darwin (around 0 days away from the next trough). Conversely, drivers in Sydney, Perth, Adelaide, Hobart are at or near the cycle low and the model is calling fill-up now before prices reset upward.
Layered over the local cycle, the macro signal is biased downward for the next four weeks based on the wholesale cost trajectory. That doesn't always change the day-to-day call, but it does shift where each city's cycle is likely to land relative to recent history.
How this update is generated
Each day at 6:00am AEST, PetrolPulse fetches the latest Brent crude spot price and AUD/USD exchange rate, then combines them using the standard Singapore MOPS import parity formula to estimate the 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 the city was trending up or down on the day, 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.