According to the Australian Institute of Petroleum, the national average price of petrol fell by 1.4c a litre last week to 150.2c, but Canberrans were paying an average 157.4c. The average metropolitan price fell by 1.9c to 147.8c a litre, while the regional average fell only 0.4c to 155.2c.

But CommSec economist Savanth Sebastian warned motorists petrol prices were set rise this week.

“Fuel prices seem to have ratcheted higher today and given the fall in the global oil price, motorists would be best placed holding up from filling up the vehicle for as long as possible,” he said.

Darwin remains the most expensive capital city at 173c a litre followed by Hobart at 160.8c and Canberra at 157.4c a litre.

While Sydney, Melbourne and Brisbane recorded declines of between 3.5 and 3.9c a litre, Adelaide recorded an increase of 8.5c a litre. Prices also increased by 0.6c in Perth to 153.3c a litre.

Average retail prices are calculated as the average of each State/Territory's metropolitan and non-metropolitan retail prices and the number of registered petrol vehicles.

Average petrol prices in the week to Sunday, May 2