Petrol prices lifted slightly last week but have been trending downwards ahead of the return of the full fuel excise tax next month.
Wholesale fuel prices dropped by 2.6 cents a litre last week, according to Australian Institute of Petroleum data.
However, the national average unleaded price rose for the first time in six weeks, increasing by 3.6 cents a litre.
Last week, motorists were paying $1.72 a litre at the pump, on average.
CommSec chief economist Craig James said the end of fuel cycles in some of the bigger cities was behind the uptick in national retail prices.
Brisbane and Melbourne approached the top of their fuel cycles last week, with motorists paying $1.82 a litre and $1.72 a litre, respectively.
Sydney was halfway through its petrol-price peak, and Adelaide and Perth were still at the start of their fuel cycles, meaning cheaper fuel remains easier to find in these cities.
Petrol prices were still well below the June peak, the data revealed, with fuel 25-50 cents a litre lower than the highs two months earlier.
NRMA spokesperson Peter Khoury said diesel prices, while more stubborn than unleaded, were also starting to trend downwards.
Mr Khoury said the oil market remained “completely chaotic”, with the war in Ukraine continuing to limit global supplies.
On the other hand, he said concerns about the cooling global economy and China’s stance on COVID-19 continued to reduce demand.
Petrol prices are expected to rise again next month when the fuel excise tax is reinstated.
The fuel excise tax was halved in May by the coalition government in response to soaring petrol prices.
The temporary tax cut shaved 22 cents off every litre.
The Labor government has committed to reinstating the tax in full in late September and has argued that extending the policy would be too costly given the government debt racked up during the pandemic.