Guide
How Petrol Prices Work in Australia
Why petrol prices go up and down, what drives the price cycle, and how to consistently pay less at the pump.
What makes up the price at the bowser?
The price you pay for petrol is built from several layers. Understanding each one helps explain why prices move the way they do.
Percentages are approximate and vary with market conditions. Based on ACCC fuel monitoring data.
The price cycle explained
If you've noticed petrol prices spike suddenly then gradually fall over a few weeks, you've observed the price cycle. According to the ACCC, these cycles happen in Australia's five largest cities and are driven by retailer pricing behaviour, not changes in wholesale costs.
The pattern works like this: one retailer raises their price, competitors follow within hours, and prices reach a peak. Then, over the following days or weeks, retailers gradually discount to attract customers. Eventually prices hit a trough, and the cycle repeats.
Canberra, Hobart, Darwin, and most regional areas don't follow regular cycles. Prices in these locations tend to be more stable but often higher due to transport costs and lower competition.
Why prices change suddenly
Beyond the regular cycle, several factors can cause rapid price movements:
- Geopolitical events like the Strait of Hormuz crisis can spike crude oil prices overnight. Australia is particularly exposed because it imports 90% of its refined fuel.
- Exchange rate movements. Australian fuel is priced in US dollars. When the Aussie dollar weakens against the US dollar, petrol gets more expensive even if crude prices don't change.
- Refinery outages. When Asian refineries that supply Australia go down for maintenance or have unplanned shutdowns, supply tightens and prices rise.
- Seasonal demand. Holiday periods and long weekends increase demand, and retailers often raise prices to match. Prices typically peak ahead of Easter, Christmas, and school holidays.
How to save on fuel
- Buy at the bottom of the cycle. In cities with regular cycles, timing your fill-up can save 10-30 cents per litre. That's $5-$15 on a 50-litre tank. See our timing guide.
- Compare prices before filling up. Use the Check Petrol map to compare live prices at stations near you. The cheapest station in your suburb is often 10-20 cents per litre less than the most expensive.
- Avoid filling up on Fridays and the day before public holidays. This is when retailers most commonly hike prices.
- Consider E10 if your car supports it. E10 is typically 3-5 cents per litre cheaper than regular unleaded 91 and works in most cars manufactured after 2005.
Frequently Asked Questions
What determines the price of petrol in Australia?
International crude oil prices (Brent crude), the refined fuel benchmark (Singapore Mogas 95), the AUD/USD exchange rate, fuel excise and GST, and local retailer competition. Changes in international benchmark prices typically take about two weeks to reach Australian bowsers.
What is the petrol price cycle?
A regular pattern in Australia's five largest cities where prices spike sharply then fall gradually. The cycle is driven by retailer pricing behaviour, not wholesale cost changes. Perth has a weekly cycle, Adelaide 2.5 weeks, and Sydney, Brisbane, and Melbourne run on longer 5-7 week cycles.
When is the cheapest day to buy petrol?
Tuesday and Wednesday are generally cheapest in most capital cities. Perth is most predictable, with Monday cheapest. Buying at the bottom of the cycle can save 10-30 cents per litre. See our detailed timing guide.
Compare live fuel prices
Check Petrol tracks prices at over 8,000 stations across Australia, updated throughout the day from official government data.