NRMA president Alan Evans predicted yesterday $1.50 a litre would become the norm through next week.

His forecast comes as the average price at service stations around the city yesterday was below $1.50 a litre, though reports suggested some Canberra outlets had bumped prices up to 154.9c a litre in the afternoon.

"My concern is that we're going to suffer from the boiling frog syndrome you raise the temperature and people will get used to it," Mr Evans said.

"The pain's there the first time when you're filling your tank, when it's over 150c a litre, but the second and third time people adjust their expenditure otherwise. And it certainly feeds into inflation."

He said the hardest hit would be people who relied on their cars.

"Our research has shown that many people who have no choice but to use motor vehicles for work and for moving their families around you can even take some of the outer suburbs in Canberra that don't have great public transport they will forgo essentials to make sure they can fill up the car to survive."

Service Station Association chief executive Ron Bowden said it was "hard to say" what would happen to petrol prices next week.

"At the moment petrol prices are only going up very, very slowly and the [Singapore] refiner margin on petrol is slowly narrowing, so that's a good sign," he said. "But it's hard to know exactly when that trend is going to change.

"Because of that and because of the strengthening Australian dollar, the impact on the Australian market is very subdued, so even though we are seeing petrol prices here edging up, they're not edging up nearly as fast as crude oil prices."

Mr Bowden said prices would stay between $1.40 and "a low $1.50" for the next week, but after that it was "anyone's guess."

Access Economics director Chris Richardson said soaring petrol prices were bad news for motorists, but the rising price of all commodities was good news for Australia's economy.

"The drive is not the US recession, it's China's strength and need for commodities," he said.

"China is still strong and that is still pushing up the price of coal and iron ore and oil.

"If you look at what markets are telling us about the strengths of the backdrop to Australia's economy, it's that Chinese strength is trumping US weakness.

"So higher oil prices are a problem for Australia, but we tend to forget that Australia's a big exporter of energy."

Australian Association for the Study of Peak Oil spokesman Elliot Fishman agreed that the emerging economies of China and India were driving up petrol prices, saying demand far outstripped supply. He said that 1964 was the year the most oil ever was discovered.

"Since that time we've been finding less and less oil and we've reached a point now where we consume four barrels of oil for every one discovered," Mr Fishman said.

"Sixty out of the top 90 oil-producing countries in the world have now peaked and they're producing less oil than they were in the past, so for Australian motorists we can expect much higher prices.

"Certainly above $2 a litre we could be paying that by the end of the year."