Petrol prices are finally starting to fall ahead of the Christmas and the holiday period in New South Wales.

The price of an average litre of unleaded could drop to as little as $1.49 over the holiday period.

There are currently significant discrepancies across the city, with some suburbs still recording high petrol prices.

“Do your research, because the gap between the cheapest and the most expensive service stations in Sydney right now is upwards of 48 cents for a litre of petrol,” NRMA spokesperson Peter Khoury said.

Current petrol prices

The current average price for a litre of unleaded is $1.68 in Sydney.

It has fallen by 12 cents over the last 15 days.

Average prices across regional NSW fell slightly by less than one cent per litre last week.

Bathurst, Wagga Wagga, Moama and Yass saw the most significant decreases in petrol prices by up to 2.9 cents a litre.

Petrol prices in Sydney reached all-time highs this year. (9News)

“It has been a tough year at the bowser for Australian families with petrol prices not just breaking records but completely hitting them out the park – Sydney’s new record highest prices is now 11 cents higher than the previous record,” Mr Khoury said.

When should you fill up?

Mr Khoury said to hold off filling the tank ahead of Christmas as “the longer you can hold off the better”.

The price of petrol is coming down by about a cent a day in Sydney and slightly slower in regional NSW.

“If you’re going to fill up before you head away there are still bargains in Sydney,” Mr Khoury said.

Mr Khoury could not say when petrol prices will hit their lowest due to the slow decrease by a cent a day.

“It’s going to take a while to get from $1.67 to what we hope will be $1.49,” he said.

“We’ve still got a way to go.”

NRMA spokesperson Peter Khoury has urged Sydney motorists to do their research before filling up. (9News)

Motorists are urged to do their research before filling up as some service stations still are tipping a high cost of petrol.

“Some service stations are always going to be more expensive than others,” Mr Khoury said.

“That’s just the nature of the industry in Australia.”

When will prices rise again?

Once petrol prices hit their lowest during the holiday period, it’s expected a significant hike in costs will occur again.

“The expectation is when we get there or thereabouts, we need to brace ourselves for an increase,” Mr Khoury said.