Fuel 
If you've ever noticed petrol jump 30 cents overnight and then drift slowly back down over the following weeks, you're not imagining it. In Brisbane and South East Queensland, regular unleaded follows a recurring price cycle - a sharp spike, then a long, gradual decline, then another spike. The whole loop has historically run around six weeks, which is where the "42-day" name comes from. Once you can read it, you can usually time your fills to land near the bottom and skip the worst of the peaks.
This guide explains what the cycle actually is, the "rocket and feathers" pattern that drives it, how to tell where prices currently sit, and when to fill up. None of it requires guesswork - you can see exactly where the market is right now on the live Fuel Daddy map, which pulls real prices from the QLD Fuel Price Reporting Scheme. It's free and there's no sign-up.
Where the cycle is in 2026: the ACCC's latest figures put Brisbane's average cycle at about six and a half weeks - the longest of any capital city (Sydney runs closer to five). There's a catch right now though: since the Middle East conflict flared up in late February 2026, the regular cycles have largely paused in Brisbane and the other big cities, with prices tracking global crude instead of the usual sawtooth. Until the normal pattern resumes, don't fill by the calendar - watch the live map for where prices actually sit.
What is the Queensland fuel price cycle?
A fuel price cycle is a recurring pattern of sharp increases followed by slow decreases in the retail price of petrol. The ACCC describes these cycles as a deliberate pricing strategy by retailers, not a response to changes in wholesale costs. In Brisbane, the cycle has historically averaged around six weeks, though the length shifts over time.
The pattern looks like a sawtooth on a chart. Prices shoot up almost overnight, sit high for a few days, then grind down day by day as stations undercut each other to win volume. Eventually a retailer "restores" prices - a fresh spike - and the loop starts again. It's worth being clear: this is a Brisbane and SE QLD phenomenon, not a regional Queensland one.
Importantly, the cycle isn't tied to oil prices or the exchange rate. The ACCC has repeatedly noted that price cycles are driven by retailer pricing decisions rather than movements in wholesale fuel costs. That's why prices can spike on a day when the global oil price hasn't moved at all. If you want the underlying drivers, our piece on why fuel prices vary in Queensland goes deeper.
Why "rocket and feathers"? The pattern explained
Economists call this pattern "rockets and feathers": prices rise like a rocket and fall like a feather. The increase phase is fast and steep - often 25 to 40 cents a litre added across one or two days. The decline phase is slow, typically shedding only a cent or two per day over several weeks.
Here's roughly how a single Brisbane cycle plays out, phase by phase:
| Phase | What happens | Should you buy? |
|---|---|---|
| The spike | Prices jump sharply - often 25–40 c/L over one or two days. Major brands usually lead. | No - worst possible time. |
| The plateau | Prices hold near the top for a few days as the rest of the market follows the increase up. | No - still near the peak. |
| The decline | Competition kicks in. Prices fall a cent or two a day for several weeks. Independents and discounters often lead the way down. | Getting better the longer it runs. |
| The bottom | Prices reach their lowest point just before the next restoration. | Yes - this is your window. |
The asymmetry is the whole game. Because the climb is fast and the slide is slow, you spend most of any given cycle in the decline phase - which means most of the time, prices are heading your way. The skill is simply not getting caught filling up on a spike day. For the day-of-week angle, our best time to buy fuel guide breaks down which days tend to land cheapest.
How do you read where the cycle is right now?
You don't have to memorise dates - the cycle drifts, so a fixed calendar won't work. Instead, read the current state of the market directly. The single most reliable signal is comparing today's lowest local price against where prices sat a week ago, which the live map shows at a glance.
Three quick tells will put you in the right phase almost every time:
- Big gap between cheapest and dearest stations. When the bottom of the market is 20–30 c/L below the dearest sites, you're deep in the decline - close to the bottom. When everything clusters tightly at a high number, a spike has just happened.
- Independents vs majors. During the decline, independents, discount suburbs and warehouse fuel sit well under the majors. When the majors and independents converge high, the restoration has landed.
- Direction of travel. If the cheapest price near you is lower than last week, the cycle is still falling - you can often wait. If it has jumped, the spike has hit and you've missed the bottom.
The honest shortcut is to stop guessing and just look. Pull up the live fuel map, check the cheapest price in your suburb, and compare it to the local average. If the gap is wide and the cheapest sites are independents, you're near the bottom - fill up. If everything's bunched high, wait a few days if your tank lets you.
When is the best time to fill up?
The best time to buy is at the bottom of the cycle, in the day or two before the next restoration. Catching that window can save 20 to 30 cents a litre versus filling at the peak - on a 50-litre tank, that's $10 to $15 a fill. Across a year of fortnightly fills, timing the cycle adds up to a few hundred dollars.
Because the bottom is a moving target, the practical rule is simple: fill a full tank when prices are clearly low, and avoid topping up on a spike. If you fill near the bottom, a full tank carries you toward the next low without you having to buy during the expensive phase. Half-empty top-ups during a plateau are where most people quietly lose money.
A few real-world tactics that work well in SE QLD:
- Buy on the way down, not the way up. Once a spike hits, there's no rush - prices only fall from there. Don't panic-fill the morning after a restoration.
- Fill completely at the bottom. A full tank at a low price beats two half-fills that straddle a spike.
- Stack a discount on top. Combine a low-cycle price with a supermarket docket and you compound the saving. More tactics in our guide to saving money on fuel.
- Pick the right fuel. E10 usually sits a few cents under regular unleaded and follows the same cycle - see E10 vs Unleaded 91 before you switch. Diesel drivers should read diesel vs petrol running costs, since diesel cycles differently.
Want to put numbers on your own driving? Plug your weekly distance and fuel use into the Fuel Daddy calculators to see what cycle-timing is actually worth to you each year.
Does the cycle work everywhere in Queensland?
No - the strong, predictable cycle is a Brisbane and South East Queensland feature. Regional centres see smaller, less regular swings because there are fewer stations competing on the way down. The further you get from the metro, the flatter and higher prices tend to be.
In and around Brisbane, the cycle is sharpest because competition is fiercest. The Gold Coast and Sunshine Coast broadly track Brisbane, often with a slight lag, and tourist strips tend to price above inland suburbs. Head a few suburbs inland and the deals improve.
Out in regional Queensland - Toowoomba, Rockhampton, Townsville, Cairns - the sawtooth flattens out. Transport costs lift the baseline, and with fewer competitors the day-to-day swings are smaller. The cycle-timing strategy still helps a little, but comparing stations matters more than timing the calendar. Either way, the live map works statewide, so you can always find the cheapest site near you.
Where does the price data come from?
Queensland runs a mandatory fuel price reporting scheme: by law, retailers must report their prices, which feeds the QLD FuelCheck system that powers tools like ours. This is why live comparison is possible at all - the data is official, not crowd-sourced guesses, and it's what makes reading the cycle straightforward.
The broader watchdog is the ACCC, which monitors fuel markets nationally and publishes regular reports on price cycles and retail margins. Their analysis is where the "rockets and feathers" framing and the cycle-length figures come from. Fuel Daddy pulls live QLD prices from the reporting scheme and NSW prices from FuelCheck, refreshing roughly every 15 minutes - so what you see on the map reflects the current state of the cycle, not a stale snapshot.
The bottom line
Queensland's fuel cycle isn't random and it isn't a conspiracy - it's a predictable retail pattern you can use. Prices rocket up in a day or two, then feather down over several weeks, looping roughly every six weeks in Brisbane and SE QLD. The winning move is boring but effective: fill a full tank when prices are clearly low, and never panic-buy on a spike.
You don't need to track the calendar to do it. Check the live map before each fill, see where the cheapest local price sits against the average, and you'll naturally land near the bottom most of the time. That's the whole trick - and it's free.
