Petrol prices set to rise over holidays

Anyone hitting the road these school holidays had better fill up quick, with petrol prices already at a four-month high expected to rise again this weekend.

National average petrol prices reached 147.4 cents a litre last week, but wholesale prices climbed 4.6 cents last week too.

NRMA's Peter Khoury said this meant retail prices could go up as soon as Friday.

He said even before the attacks on two Saudi Arabian oil processing plants earlier this month, petrol prices were set to rise.

Mr Khoury blamed that on the United States' escalating trade war with China, a weak Australian dollar and oil-producing nations cutting production to increase prices.

Melburnians, who have already started their holidays, copped the highest rise last week, with a jump of 15.2 cents a litre to 147.9 cents a litre.

To make it worse, the end of a retail discount period saw prices climb further to 164 cents a litre on Monday.

While Hobart saw the lowest rise in prices, at 0.1 cents a litre, they paid the highest average of any capital city last week, at 151.5 cents a litre.

Brisbane saw the biggest drop in petrol prices for all the capital cities last week, falling by 13.7 cents a litre, with drivers paying 139.4 cents a litre on Monday.

The national average retail diesel price also rose, climbing 0.6 cents to 147.4 cents a litre last week.