The old adage of fuel prices being cheapest on Wednesday is untrue.

FuelWatch said Perth’s weekly price cycle had been disrupted for the past two weeks.

Wednesday’s unleaded fuel price at Caltex StarMart Doubleview is $1.48 a litre — but on Sunday it was $1.17/L.

Coles Express Fremantle is also selling for $1.48/L and on Sunday it was $1.40/L.

Since November 2010, fuel retailers have increased their prices on a Thursday with the metropolitan average price gradually dropping to be cheaper on Wednesdays.

FuelWatch manager Lynne Gould said the cheapest day was now unknown.

“Some brands are increasing their prices earlier in the week, with others following that lead, making the week’s price fluctuations more erratic and less predictable,” she said.

“For this reason, motorists are advised to check the prices daily on the FuelWatch website to seek the cheapest price in their area.

“On any particular day, some brands could have the highest and lowest fuel prices on sale in the metropolitan area, so motorists should check site by site, rather than shopping by brand.”

Drivers can log onto the FuelWatch website after 2.30pm each day to compare the next day’s fuel prices.

Extracted in full from Herald Sun.