The price of petrol is at its lowest for more than four years - and an AA spokesperson says no one really knows when the drops will end.
Major fuel suppliers Z, BP and Gull have dropped the cost of petrol by 2 cents a litre after oil prices dropped again overnight.
The price of 91 Octane is at $1.89 at most petrol stations, while Gull's price is at about $1.80 and as low as $1.70 in some places.
Super is selling for $1.99 at most outlets, while diesel is at $1.22.
Oil has shed about half its value since June, and Brent Crude dropped to the lowest it's been in five-and-a-half years before settling at $US57.41.
AA spokesperson Mark Stockdale said fuel prices had not been as low since 2010.
"No one really knows exactly where it's going to end," he said.
"The commodity prices continue to fall. They're falling probably lower than what any experts had expected.
"How far will they fall? Will they eventually stabilise or will they go back up again? We just don't know."
Slow growth in China, a recession in Japan and a near-stall in the Euro zone had all contributed to the falling oil price.