Massive Monday night queues at Perth petrol stations may be a thing of the past, with FuelWatch reporting a “disruption” to the weekly fuel cycle.

For the past five years, petrol stations in Perth have stuck to a weekly price cycle, generally selling the cheapest fuel on Mondays before a sharp price rise on Tuesdays.

But all that could be about to change, with FuelWatch manager Ben Derecki saying Caltex, Caltex Woolworths, Puma, 7-11 and United stations are all dropping their petrol prices today.

Mr Derecki said while it could be another week or two before Perth drivers will know if a new pattern was being established, only Coles Express and BP were increasing their petrol prices today.

“Most major branded retailers are still continuing to drop their ULP price (today), so further savings can be made by holding off your petrol purchase for another day,” he said.

And while Mr Derecki said he did not know exactly why the change had happened, he said price cycles were generally used by businesses to “maximise profits”.

Perth is the only market in Australia that has a weekly cycle, with the cycles in other Australian capital cities ranging from two to eight weeks.

Prior to June 2015, the cycle involved prices being increased on a Thursday.

Check the FuelWatch website for the latest petrol prices around WA.