Petrol prices have lifted for the second time in seven weeks but average fuel costs remain well below the peaks above $2 a litre seen earlier in the year.

Motorists are paying $1.77 a litre at the pump on average, up by 4.9 cents from last week.

Wholesale petrol prices lifted modestly by 2.8 cents to $1.55 a litre, according to Australian Institute of Petroleum data.

The uptick comes as the expiry date on the discounted fuel excise looms.

Motorists can expect to be paying an extra 22 cents a litre in September when the fuel excise tax is reinstated in full.

Of the major capitals, Sydney saw the sharpest uptick in fuel prices last week of the major capitals, with motorists now paying $1.83 a litre, on average, which is an 11.8 cent lift.

Melbourne prices also jumped to $1.83 a litre, representing a 10.8 cent rise.

Fuel prices in Adelaide eased by 12.2 cents, with motorists in the city paying $1.56 a litre, on average.

Prices in Hobart, Darwin and Canberra also softened slightly.

Crude oil prices rose last week following news that the Organisation of Petroleum Exporting Countries was considering reducing supply to stabilise the oil market.

On Friday, the Brent crude oil price rose by $US1.65, or 1.7 per cent, to $US100.99 a barrel.