Average daily petrol prices in the last month.
The nation's petrol price watchdog admits Perth fuel prices have been behaving strangely, but he has no concerns - yet.
BP has twice in recent weeks hiked unleaded petrol prices by up to 13 cents a litre, despite falling international fuel costs. BP claims it needed to increase its "unsustainable" retail margins.
The oil major's move has twice been mirrored by others as it remains the price-setter in WA, due to its ownership of the Kwinana refinery.
The price rises have meant that for 11 days in the past month, Perth motorists have had to contend with rising fuel prices, despite falling oil costs worldwide, including the Singapore benchmark used to set Australian prices.
Petrol Commissioner Joe Dimasi told WAtoday.com.au he was puzzled with the behaviour of Perth prices in recent months.
"Prices there have been behaving very strangely compared to the rest of the country," he said.
"The price cycle seems to have disappeared, but it does reflect the market conditions in Perth."
The petrol price cycle, which took anywhere from a week to a fortnight in the past, has not been in evidence in Perth since about May last year .
It has been slammed by FuelWatch and motoring advocates as being of benefit only to retailers.
However, Mr Dimasi said Perth prices "were not that bad" compared to the rest of Australia. They were lower overall for the month than Sydney and Melbourne.
"On balance it seems to me we're seeing some fairly strange behaviour of (oil industry) players trying different tactics, but the market seems to be holding prices comparable to anywhere else."
"If there was any signalling on prices (between retailers), we'd be getting concerned, but I don't think there is.
"When a player tries to put prices up, competition should whittle away the price increases, and that seems to be happening."
While he had no immediate concerns, he was "keeping a close eye" on what went on in the Perth market, given that the Singapore and world prices continued to head downwards.
"If we don't have an explanation, we'd have to start looking at the behaviour of the participants, but the indication to me at the moment is that whoever is trying to put prices up hasn't succeeded."
Though BP controlled the Kwinana refinery, Mr Dimasi said he was satisfied there was enough competition to stop it hiking wholesale prices beyond a reasonable level, with the likes of WA-owned Gull able to import fuel and others able to do deals to get lower prices.
"(WA) is
still part of the Australian market and others can compete with BP, and are
competing," he said.
