There are some encouraging signs for consumers, with petrol prices likely to slide by as much as 10 cents per litre in the next few weeks.

It comes after a slump in global commodity prices at the end of last week.

The latest figures from the Australian Institute of Petroleum show the national average price of unleaded petrol rose by 1.3 cents per litre to almost 146 cents last week.

But an economist at Commsec, Savanth Sebastian, says lower world oil prices will bring local fuel costs down, offering a reprieve for household budgets.

"Prices will probably fall by about eight to 10 cents per litre, and that's a substantial saving - it means about $7 less when you fill up a 70-litre tank of fuel," he said.

Mr Sebastian says motorists are likely to make some substantial savings in the coming weeks.

"We have seen that the Singapore unleaded price fell by its biggest weekly margin since September 2009 and those substantial falls on a global level will filter through to domestic prices in a fortnight or so time," he said.

Mr Sebastian says household budgets have been under serious pressure with petrol prices at 30-month highs.

"[There will be] some reprieve for consumers, and that could be a good sign going into the second half of the year as well," he said.

"If we do see that petrol prices remain relatively subdued, we may see that that lack of consumer spending turns the corner."