Drivers who top up their tanks at Coles Express are in for a huge shock, with outlets breaking with Perth’s two-week petrol cycle and hiking up prices.

From 6am Wednesday, all but six of the metro area’s Coles Express sites will bump their ULP price by up to 39 cents per litre to 235.9cpl.

“For the second consecutive time, Coles Express sites have broken with Perth’s fortnightly petrol price cycle by hiking their prices mid-cycle,” a spokesperson for WA’s Department of Mines, Industry Regulation and Safety said on Tuesday afternoon.

Perth traditionally reaches a fuel low-point every second Tuesday, before spiking heavily the following day.

While Coles manages the convenience stores on these sites, it was quick to point out the price of fuel is set by Viva Energy Australia, which has been sought for comment.

“Coles Express’ petrol price hike tomorrow mid-cycle may be an attempt to disrupt Perth’s fortnightly petrol cycle but it is yet to be seen if the other retailers will follow,” FuelWatch manager Ben Derecki told The West Australian.

“Wednesday July 6, is the mid-point of Perth’s fortnightly cycle, and although most Coles Express sites are selling ULP for 235.9cpl, many other metro retailers are selling close to the wholesale price of 196 cpl (some selling below), meaning they are likely making a loss on ULP sales when taking into account operating costs.

“In saying this we recommend that, if they can, motorists hold out filling up their car until the coming Monday and Tuesday when petrol prices are expected to be at their lowest for the current fortnightly cycle.”

Perth’s metro average will sit at 207.2cpl on Wednesday, although 100 of Perth’s cheapest options will range between 193.5cpl and 199.9cpl.

BP will also increase its price by 1.7cpl, while the cost of fuel from Caltex/Ampol, 7-Eleven, Puma, United and Caltex Woolworths will drop between 1.2 and 2.5cpl from Wednesday morning.

The news comes on the same day the Reserve Bank hiked the cash rate to 1.35 per cent.

RateCity estimates the 50 basis point rise – the third hike in three months – will add $137 a month to a $500,000 mortgage, or $499 per month on a $750,000 loan.

“Today’s increase in interest rates is a further step in the withdrawal of the extraordinary monetary support that was put in place to help insure the Australian economy against the worst possible effects of the pandemic,” Reserve Bank governor Phil Lowe said in a statement following Tuesday’s board meeting.

“The resilience of the economy and the higher inflation mean that this extraordinary support is no longer needed.”

He said the size and timing of future interest rate rises would be guided by “the incoming data and the board’s assessment of the outlook for inflation and the labour market”.

“The board is committed to doing what is necessary to ensure that inflation in Australia returns to target over time.”

The board is seeking to use rate rises to push inflation down from its 21-year high of 5.1 per cent back into its two to three per cent target band.

But global and domestic factors are pushing inflation towards a predicted peak of seven per cent by the end of the year.

“Inflation is forecast to peak later this year and then decline back towards the two to three per cent range next year,” Dr Lowe said.

Extracted in full form: Perth petrol: Price of unleaded at Coles Express outlets across city to surge to 235.9cpl | The West Australian