The national average price of unleaded petrol rose by 3.5 cents to $1.45 a litre in the week to Sunday, according to the Australian Institute of Petroleum.

That's the highest level since mid-November, with prices ranging from $1.35 to $1.58 across capital cities.

CommSec senior economist Ryan Felsman expects unleaded petrol will remain at about $1.50 for a while.

He says last week's price spike came at the end of the discounting cycle in Brisbane, Sydney and Melbourne.

Crude oil prices have also been on the rise for the past six weeks, amid OPEC and Russian-led product cuts and supply disruptions in Venezuela, Libya and Sudan.

Mr Felsman says there could be some respite from rising oil prices in the second half of this year, if Russia withdraws from its supply-cut pact with Saudi Arabia while US drilling activity and production increases.

But Australian consumers are likely to remain cautious about splashing their cash.

"Announced tax cuts from July 1 could boost consumption, but the strength of the jobs market remains key to the interest rate outlook."

Australian Associated Press