In Adelaide, Melbourne, Sydney and Tasmania the highest price today was above $1.62 per litre, while motorists in the Northern Territory have been copping prices in excess of $1.60 for more than a week.

In Brisbane, prices were hovering around the $1.30 mark in some parts of the city, according to motorist information website motormouth.com.au.National Australia Bank economist Gerard Burg said it was unlikely prices would stabilise in the short term.

"Obviously we're seeing a steady increase in world oil prices and that's been capturing headlines," Mr Burg said.

"There's a lot of uncertainties at play in the domestic market when it comes to the petrol prices," he said, pointing to the strong Australian dollar which is significantly easing pressure on the petrol price.

The dollar ended slightly lower today, off its 24-year high of recent days.

Crude oil is traded in US dollars, meaning Australia's strength against the greenback is offsetting rising crude prices.

Mr Burg said the recent decision by the Organisation of Petroleum Exporting Countries (OPEC) to refuse requests for a rise in oil production would not help.

"There's no reason to expect prices to fall away from these levels anytime soon."

In Melbourne the price rose to $1.63 at one service station in the city's south-east.

Victorian motoring group the RACV said the spike was part of the mysterious weekly price cycle which even an extensive 2007 investigation by the competition watchdog could not unravel.

The service station was charging the steep price despite a nearby rival station charging just $1.36, RACV spokesman David Cumming said.

"If others don't follow, that's the end of it," he said."It's just someone trying it on."

NSW motoring body the NRMA reported the top price in Sydney was almost $1.63.

"Crude oil prices continue to rise and continue to break records and we're seeing the same at the bowser with quite dramatic effects on Australian families and also on the economy," an NRMA spokesman said.

"These prices have already hit Sydney and tomorrow is Thursday - the most expensive day of the week - so motorists need to brace for even more pain."

The lowest bowser price recorded across Sydney today was 138.9 cents a litre.

OPEC has steadfastly refused to increase output with the group's secretary-general Abdullah Al-Badri today saying the high price of crude was a result of the weakened US dollar, not the fundamental issue of supply and demand.