Victoria
Sunbury: Tuesday was the lowest day in 8 of 12 full weeks, about 1.4 c/L under its weekly average.
Best day to buy petrol in Australia (2026)
There is no fixed cheapest day for petrol.
By the FuelRadar team2 min read
Cheapest day to fill up in Perth
Wednesday has been the cheapest day in Perth, about 6.8 c/L below the week's average.
Source: FuelRadar (fuelradar.com.au) · data as at
The cheapest day in each regional town
Measured from each town’s own station prices over the last 13 weeks
Queensland
Gold Coast: Tuesday was the lowest day in 11 of 12 full weeks, about 1.9 c/L under its weekly average.
Is there a cheapest day to buy petrol?
There is no fixed national cheapest day. Sydney, Melbourne, Brisbane and Adelaide have multi-week cycles whose start and duration change over time. Perth currently has a seven-day unleaded petrol cycle, but the useful check is still the notified price at the stations you can reach.
Use the current cycle, not a weekday rule
A retail petrol cycle usually rises over a short period and then falls more gradually. The ACCC reported that average cycle lengths in 2025 ranged from about one week in Perth to about six and a half weeks in Brisbane. That makes old advice such as “always buy on Tuesday” unreliable outside a specific current market pattern.
Current guidance by city
| City | 2025 average cycle length | Useful check |
|---|---|---|
| Sydney | About 5 weeks | Current ACCC buying tip and nearby station reports. |
| Melbourne | About 6 weeks | Current cycle position rather than a fixed day. |
| Brisbane | About 6.5 weeks | Current cycle chart and local station spread. |
| Adelaide | About 2.5 weeks | Whether the current market is rising or easing. |
| Perth | About 1 week | FuelWatch prices for today and tomorrow. |
How to check before a fill
- Choose the exact fuel grade your vehicle uses.
- Check the current city cycle or buying tip.
- Compare nearby service stations by reported price, distance and update time.
- If prices have started rising, check whether another nearby retailer has not moved yet.
- Confirm the final price at the bowser.
Perth and Western Australia
FuelWatch requires covered retailers to notify prices for the next day and hold that price from 6am for 24 hours. Tomorrow's prices are available after 2:30pm. Compare today and tomorrow, then choose a station that fits your route. The current seven-day cycle applies to unleaded petrol, not diesel or LPG.
How much does a price gap change the tank cost?
A 15 c/L difference changes a 60-litre fill by $9. A 20 c/L difference changes it by $12. Compare that gross saving with the extra distance before travelling across town.
Official buying tips
The ACCC petrol price-cycle page publishes current buying tips and charts for the five largest cities. Western Australian drivers can check FuelWatch for today and tomorrow prices.
The capitals ranked by their best day (Unleaded 91)
1 of 8 capitals have a reliably cheaper weekday. Each capital's lowest day on average is listed with its gap under the week and the full weeks it was the low, the reliable days first, then the largest gaps. Each day is compared with the average of the seven days around it, so a rising or falling market cannot make one weekday look cheaper. A day is reliable only with a gap of at least 2 c/L and the low in most full weeks. Based on reported daily Unleaded 91 city averages over the last 90 days, full weeks to 12 Nov 2026. A weekday pattern can change, so check the current cycle and nearby station reports before a large fill.
| Rank | Capital | Lowest day | Under the week (c/L) | Weeks it was the low | Reliable? |
|---|---|---|---|---|---|
| 1 | Perth | Wednesday | 6.8 | 12 of 12 | Yes |
| 2 | Melbourne | Tuesday | 0.9 | 3 of 12 | No |
| 3 | Darwin | Monday | 0.6 | 4 of 12 | No |
| 4 | Canberra | Monday | 0.5 | 4 of 12 | No |
| 5 | Sydney | Monday | 0.3 | 3 of 12 | No |
| 6 | Brisbane | Monday | 0.2 | 1 of 12 | No |
| 7 | Hobart | Sunday | 0.2 | 2 of 12 | No |
| 8 | Adelaide | Wednesday | 0.1 | 4 of 12 | No |
Common questions
What is the cheapest day to buy petrol?
There is no dependable national cheapest weekday. Use the current ACCC buying tip or local cycle chart, then compare station reports for your fuel grade.
When do petrol prices go up?
The timing changes by city and cycle. Retail prices can rise over a short period and then fall more gradually, so check the current chart rather than an old weekday rule.
How do I check tomorrow's petrol prices in Perth?
FuelWatch publishes tomorrow's notified prices after 2:30pm. Covered retailers must hold the notified price from 6am for 24 hours.
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