The metropolitan average price rose by two cents per litre to 141.9 cents, while the regional average rose by 3.4 cents to 144.7 cents.
CommSec economist Savanth Sebastian says unleaded prices are now at a ten-week high and there are few signs that the bad news will ease.
"Rather, the latest round of data seems to suggest that further substantial price gains are on the horizon," he said in a statement on Monday.
"The bottom line is that the average Australian pump price for petrol should continue to edge higher."
To avoid being slugged with high petrol prices motorists should time when they fill their tanks, Mr Sebastian said.
"Not only is the discounting cycle continuing to change within capital cities but price trends are far from uniform across cities."
20 Aug 2012