finder Petrol Price-Cycle Predictor Prototype · sample data

Sydney · Updated Tue 20 Oct 2026

Should you fill up today?

Sydney's petrol price cycle has peaked again. We track the cycle, call the top and the bottom, and tell you one thing: buy now, or wait.

Sydney average (U91)
241.8c+89.0c since 23 June
Cycle stage
PeakDay 2 of a ~35-day cycle
Predicted low
~168cAround Tue 3 November
Today's call

Wait

Prices are within 3% of the cycle peak.

ConfidenceHigh · 86%

  • Today's Sydney average of 241.8c/L is the highest point of the current cycle — and the highest in 2026 so far.
  • The last three cycles all fell 45–60c from peak to trough over roughly four weeks.
  • Wholesale (TGP) pricing has already turned down, which typically leads the pump by 5–8 days.

If you're running on fumes: put in 15–20L to get you through, then fill the tank properly when the cycle bottoms out. A splash-and-dash at the peak costs far less than a full tank at the peak.

55L

Saving if you wait

$40.37

The Sydney cycle, mapped

Petrol prices in Sydney don't drift — they saw-tooth. A sharp 40–60c spike over a few days, then a slow slide for three to four weeks. Fill up on the wrong day and you pay for someone else's bad timing.

Unleaded 91 · Sydney metro average

23 June – 3 November 2026

  • Actual average price
  • Finder forecast
  • Today (241.8c)
  • Cycle low — best day to fill
Three full cycles since June. Each one peaked hard and bled down over four to five weeks — the troughs came in at 158.9c, 163.5c and 170.9c. Today sits at 241.8c, inside the peak zone. We expect the next low around 3 November at roughly 168c.
View the data behind this chart
Sydney unleaded 91 weekly average, cents per litre
WeekPriceCycle position
23 Jun 2026152.8cCycle low
30 Jun 2026198.4cCycle peak
7 Jul 2026188.1c—
14 Jul 2026176.5c—
21 Jul 2026165.2c—
28 Jul 2026158.9cCycle low
4 Aug 2026211.3cCycle peak
11 Aug 2026199.7c—
18 Aug 2026187.4c—
25 Aug 2026174.8c—
1 Sep 2026163.5cCycle low
8 Sep 2026222.6cCycle peak
15 Sep 2026210.2c—
22 Sep 2026196.8c—
29 Sep 2026182.3c—
6 Oct 2026170.9cCycle low
13 Oct 2026228.4c—
20 Oct 2026241.8cToday — cycle peak
27 Oct 2026214.5cForecast
3 Nov 2026168.4cForecast

Where we are in the cycle

Every Sydney cycle moves through the same four stages. Knowing which one you're in is the whole game.

Stage 1 You are here

The spike

Prices jump 40–60c in 48–72 hours as retailers reset margins. Worst possible time to fill a tank. Lasts 2–4 days.

Stage 2

The early slide

Discounters undercut first and the average falls 3–6c a week. Still 30c+ above the bottom. Patience pays here.

Stage 3

The grind down

Weeks three and four. The spread between cheapest and dearest station blows out to 40c — shopping around matters most now.

Stage 4

The trough

The bottom 3–5 days of the cycle. Fill up, and lock the price if your retailer lets you. Then the spike starts again.

The Fuel Lock strategy

Several retailers let you lock a price in their app and redeem it later — usually up to 150 litres within 7 to 30 days. Used properly, it turns one good day into a month of good days. Used badly, it freezes you into the peak.

  1. Wait for the trough, not the headline.Lock only when the cycle is in its bottom 3–5 days. Our predictor flags that window — right now it's around 3 November.
  2. Lock the lowest price you can see, not the one at your usual servo.Lock prices are usually set from a specific site. Check a few nearby before you commit — a 12c difference on 150L is $18.
  3. Redeem across multiple fills.A 150L lock is roughly three tanks. Use it through the spike, and re-lock at the next trough. Done right you never buy at the peak again.

When it works — and when it doesn't

  • Works: you lock at the trough and the cycle spikes within your lock window. Typical saving: 40–60c/L.
  • Works: you drive 300km+ a week and will realistically burn 150L before the lock expires.
  • Works: you stack it with a loyalty discount that still applies at redemption. Check the terms first.
  • Doesn't: you lock during the spike. You've guaranteed yourself a month of the worst price of the cycle.
  • Doesn't: you only use 40L a month. Most of the lock expires unused and the admin isn't worth it.
  • Doesn't: the lock is tied to premium fuel you don't need. Locking 98 when your car takes 91 is a loss on day one.

Today's Fuel Lock call: don't lock.

Locking 241.8c for 30 days would guarantee you the worst price of the cycle. Set a reminder for the week of 3 November — on our forecast that's about 73c/L cheaper, or roughly $110 saved across a 150-litre lock.

Get the trough alert

We'll send one notification when Sydney's cycle bottoms out — and nothing else. No daily price spam.

Read the Fuel Lock guide

How the predictor works

Where do the numbers come from?
This page is a prototype. Every price, date and forecast on it is illustrative sample data built to demonstrate the product — it is not a live market feed and should not be used to make real purchasing decisions. A production version would run on daily retail price data and terminal gate pricing.
Why does Sydney have a price cycle at all?
Cycles are a retail pricing strategy, not a response to the oil price. Retailers lift margins sharply in a coordinated-looking spike, then undercut each other down to near cost over the following weeks. Crude oil moves far too slowly to explain a 50c swing in three days.
How accurate is the trough prediction?
The model in this prototype is illustrated as calling the trough within ±3 days and the trough price within ±6c/L. Cycles can be cut short by a crude price shock or stretched out by a public holiday weekend, so treat any date as a window rather than a deadline.
Does this work outside Sydney?
Melbourne, Brisbane and Adelaide all run cycles on their own clocks, so the same method applies with different timing. Perth runs a strict weekly cycle — Tuesday is almost always the day. Regional areas and Canberra don't really cycle at all, so there the advice is simply to shop on price, not timing.