The NRMA is accusing oil companies of stockpiling premium petrol as Canberra prices look set to climb above $1.50 a litre just in time for the school holidays.
President Alan Evans said yesterday the NRMA was concerned about premium unleaded pumps being closed by stations on Tuesdays.
"We have had a supposed shortage of premium unleaded for four months," he said.
"I think there are supply issues but the oil companies, knowing the supply issues, don't make it available [on Tuesdays], so they get the maximum on the higher priced days, like Thursdays," he said.
Crude oil futures topped $112 a barrel in New York on Tuesday a record after a weekly US government report showed an unexpected decline in inventories.
Mr Evans warned it could mean more pain at the pump for drivers next week.
Across Canberra yesterday, unleaded petrol was selling for $1.49 a litre and some reports suggested prices above $1.50 a litre may be the norm around Australia for the rest of the year.
"That [price rise] will put additional stress on families, as it will cost them a few more dollars to fill up their tanks," Mr Evans said.
He called on the Australian Competition and Consumer Commission's new Petrol Commissioner, Patrick Walker, to ensure "that the refinery margin and the retail margin are at a fair level".
Mr Walker agreed that price rises would not be felt until next week because of "the seven-day rolling cycle".
"The rough rule of thumb is $1 a barrel is a cent a litre. Clearly, Australian prices are influenced by two major factors the price of oil per barrel and the Aussie dollar," he said.
Mr Walker said Australian prices were set by the Singapore benchmark, but the major influence on the Singapore benchmark was the cost of oil.
He warned that although the rolling price cycle was intended to average out prices, rises and falls would still filter through to Australia.
Mr Evans said Mr Walker should have additional powers to punish oil companies if they were found to be profiteering or stockpiling petrol.
"He [Mr Walker] should also be able to recompense motorists if they have been overcharged," he said.
But Mr Walker said he believed his powers were to investigate at the moment.
And he said investigations by the ACCC and the NSW Office of Fair Trading had not revealed any "systemic cases of people withholding [premium] fuel".
"Having said that, there is still one or two matters that we are continuing to follow up."
Around Canberra yesterday, motorists filling their cars at petrol stations were not surprised to hear of more pain on the way at the bowser.
Matthew, of Queanbeyan, said he worked as a scaffolder and found it hard to avoid driving in his job.
"I try to fill up once a week, but probably it's twice," he said.
"You try not to let it get you down, it could be worse.
"Petrol is just one of those things you need."
And Dennis, of Womboin, said he had not realised he had chosen the cheapest station in Fyshwick to fill up at.
"It's too expensive, [but] you cop it on the chin.
"I need petrol regardless of the price," he said.