Fuel prices in Western Australia

Western Australia's fuel market works unlike anywhere else in the country. Under FuelWatch's 24-hour rule, stations must lock in tomorrow's price today — and then hold it for a full 24 hours. It makes WA the only state where you can plan a fill-up with certainty about what you'll pay.

How the FuelWatch 24-hour rule works

Every WA service station must notify FuelWatch of tomorrow's prices by 2pm today. Those prices take effect at 6am the next morning and cannot be changed for 24 hours.

FuelWatch publishes the following day's prices to the public from about 2:30pm each afternoon. That's the key advantage: a WA driver can look tonight, see exactly what every nearby station will charge tomorrow, and decide accordingly.

It also removes a frustration common elsewhere — arriving to find the cheap price you saw has already been raised. In WA, that can't happen within the day.

Perth's weekly price cycle

Perth is the exception to the "cycles are unpredictable" rule. It runs a genuine weekly cycle, with prices typically peaking around Wednesday or Thursday and bottoming out on Monday or Tuesday, week after week.

Tuesday is usually Perth's cheapest day, and the difference across the week is substantial. ACCC analysis has found that around 30% of Perth's retail petrol volume is sold on Tuesdays — drivers there have learned the pattern.

Combining the two features is the WA advantage: check tomorrow's published prices on a Monday afternoon, and you know exactly where to fill on Tuesday.

Where fuel tends to be cheapest in WA

Within Perth, the northern and southern outer suburbs with clusters of independents typically undercut inner areas. Membership sites like Costco at Perth Airport and Casuarina often set the floor price for the metro area.

Regional WA is a different market. Bunbury, Geraldton, Kalgoorlie, Albany and Broome have enough stations to compete, but prices rise steeply once you're beyond them.

On remote routes — the Great Northern, Eyre and Nullarbor highways — the gap between town prices and roadhouse prices is the largest in Australia. Fill in town every time you can.

Frequently asked questions

What is the FuelWatch 24-hour rule?

WA service stations must notify FuelWatch of the next day's prices by 2pm. Those prices start at 6am the following morning and are locked for 24 hours. It's why WA is the only state where you can see tomorrow's fuel prices tonight.

What day is petrol cheapest in Perth?

Tuesday, usually. Perth runs a genuine weekly price cycle that typically peaks Wednesday or Thursday and bottoms out Monday or Tuesday. ACCC analysis has found roughly 30% of Perth's petrol volume is sold on Tuesdays.

Can WA stations change their price during the day?

No. Once a price takes effect at 6am it's fixed for 24 hours. That's unique to Western Australia — everywhere else, a station can raise its price at any time.

Why is regional WA fuel so much more expensive?

Distance. Remote WA roadhouses sit hundreds of kilometres from supply and often have no competitor nearby. The price gap between regional towns and remote roadhouses is the widest in the country.