The RAA has accused petrol giant Caltex of trying to manipulate Adelaide’s fuel cycle to catch out unsuspecting motorists amid warnings prices will experience their biggest increase in nearly 25 years.

RAA senior analyst Chris West said the Caltex behaviour in South Australia followed its success in disrupting the fuel price cycle in Perth, where the weekly Thursday spike and later discount had been thrown into chaos because Caltex started spiking prices on Tuesdays.

“For the last three spikes in Adelaide over the last nine to 10 weeks we have seen Caltex move quicker than all the three other majors,’’ he said.

“It is a change in their pricing strategy, because previously Caltex of their 30-odd sites would only send prices at a couple up in the first 12-hour period and then a couple more in the second 12-hour period.

“Now they are moving all their sites at once, which is a massive change, and that is catching motorists out because they can’t see the slow change in the market and react to it. We are encouraging motorists to shop elsewhere.’’

The average ULP retail fuel price in Adelaide on Tuesday was 148.1c and hit a three-month high of 148.9c at the weekend, according to RAA figures.

The lowest price in the past three months was 118.1c on April 8.

Australian Institute for Petroleum figures, published by CommSec on Tuesday, show the pump price has increased by 13.1 per cent so far in the June quarter.

CommSec warned petrol prices still have further to increase — owing to higher refinery prices in Singapore — putting them on track for their biggest three-monthly rise since the December quarter of 1990.

CommSec chief economist Craig James said the national average fuel price $1.10 per litre at the beginning of the year, but last week jumped to $1.42.

Mr West would not confirm the predictions, but said the price in Adelaide was far too high.

“What I would say is that the $1.49 per litre we were paying in Adelaide last week is highly inflated and is an outrageous price, 20 cents above cost price and cannot be justified,’’ he said.

“As part of the fuel cycle we expect to see that fall to the $1.30 mark.’’

Extracted in full from Perth Now.