The month in numbers
| National wholesale, c/L | Petrol | Diesel |
|---|---|---|
| 31 July | 184.1 | 224.4 |
| 3 August, full excise | 204.2 | 246.2 |
| 12 August, low | 190.6 | 230.9 |
| 31 August | 196.5 | 239.2 |
| Change over the month | +12.4 | +14.8 |
| August average | 195.9 | 239.5 |
| July average | 169.7 | 198.3 |
The excise step
From 3 August excise went from the temporary 36.6c a litre back to the full rate, indexed to 53.7c. With GST that is 18.8c a litre. Wholesale petrol rose 20.1c between Friday 31 July and Monday 3 August, and diesel 21.8c, both slightly more than the excise change because oil was firming at the same time. Our guide to what the 2026 excise cut did to prices has every step of it.
Take the tax out
Over the whole month wholesale petrol rose 12.4c a litre. The excise change accounted for 18.8c of that, so the fuel itself got about 6c cheaper.
Diesel was similar, up 14.8c over the month, about 4c less than the excise change. Brent averaged US$88.24, a little above July's US$84.85, but the Australian dollar strengthened from an average of 69.7 to 71.1 US cents, which offset most of it. Prices eased for the first week and a half after the excise rise, reaching their low for the month on 12 August, then edged back up over the rest of the month.
City by city
| City | Petrol 31 Aug | Change in Aug | Diesel 31 Aug | Change in Aug |
|---|---|---|---|---|
| Perth | 195.3 | +12.0 | 233.8 | +13.6 |
| Adelaide | 195.3 | +11.5 | 238.5 | +14.1 |
| Melbourne | 195.6 | +12.5 | 241.2 | +15.4 |
| Sydney | 197.0 | +12.7 | 240.5 | +15.3 |
| Brisbane | 197.4 | +12.7 | 240.6 | +15.3 |
| Hobart | 199.8 | +11.9 | 241.4 | +13.6 |
| Darwin | 204.2 | +12.2 | 249.9 | +14.3 |
Terminal gate prices, cents a litre, change from 31 July to 31 August, from the Australian Institute of Petroleum.
Perth and Adelaide shared the cheapest petrol at the end of the month, and Perth had the cheapest diesel by almost 5c. Darwin was the dearest for both, as it has been for most of 2026.
What it meant at the pump
A fair pump price for regular unleaded in the capitals moved from about 194 to 199c at the end of July to about 207 to 212c at the end of August. Because the excise change landed on a known date, it was one of the few price rises drivers could see coming. Filling up on the weekend of 1 and 2 August saved around 19c a litre on a tank.
What came next
The easing did not last. Brent went back above US$100 on 9 September and wholesale petrol rose 35c a litre during the month. The September report covers it.
Where these figures come from
Wholesale prices are the terminal gate prices published each weekday by the Australian Institute of Petroleum, which we hold back to 2004. The national figure is AIP's own average where it has published one, and our weighted calculation in between, which matches AIP's to within 0.1c. Oil and currency prices are delayed market closes. Excise rates are the ATO's. We check every figure against that data before publishing and correct mistakes in the update log. Spotted one? Email hello@thepetrolprice.com.