Petrol stations are required by law to update their pricing in real-time, which the Department of Fair Trading uses to update the Fuel Check website.

The NRMA is warning drivers to expect price rises on both unleaded and diesel fuels across the three-day span as service station operators look to capitalise on the increased volume of traffic on the roads.

There’s already been evidence of a spike in petrol prices, with regular unleaded costing an average of 0.4 cents per litre more in regional NSW than it did a week ago.

It’s a similar story with diesel, which has risen in price by about 0.5 cents per litre across the same seven-day stretch.

NRMA spokesman Peter Khoury said motorists should look to fill up now before heading away.

“The gap between the cheapest and most expensive service stations can be up to 35 cents per litre,” Mr Khoury said.

“With prices expected to rise in the coming days that gap could worsen, so it’s important to do your research and fill up as soon as possible.”

Mr Koury advised “the average family could save as much as $20 on a tank of regular unleaded” if they shopped around.

According to the state government’s Fuelcheck website, the state’s average price for regular unleaded was 123.9 cents per litre.