It's different to the "fill up now" advice given to Sydney motorists, because the two markets have differences in price cycles, said the NRMA's Peter Khoury.

"What tends to happen in Wollongong is the trend is the same but the numbers aren't exactly the same," Mr Khoury said.

"So you won't go as high as we do, but you won't go as low either."

While Sydney has hit the bottom of the price cycle at 134.3 cents a litre, Wollongong's average is sitting at 145.3 and Mr Khoury said that will likely drop through the week.

"The Illawarra dropped almost three cents last week so it is falling," he said.

"That's 2.8 cents in the last week. Those falls are likely to continue to be quite moderate but hopefully they should continue along that trend."

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Mr Khoury said, with the long weekend approaching, drivers will benefit from the petrol price cycle.

"Unlike the Easter and Anzac Day holiday period the fuel cycle is actually working in the favour of motorists heading into the long weekend," he said.

With further drops expected in the coming days, Mr Khoury said the NRMA's advice for Wollongong motorists is hold off on buying petrol if you can.

"If you can wait, by all means do that," he said.

"It's a different message to Sydney. Sydney's probably at the bottom now, or very close to it.

"If you do need to go to the petrol station, maybe just top up, don't full up the whole tank.

"You may get better prices further on down the week."

As of Tuesday morning, there was a wide range of petrol prices for regular unleaded in the Illawarra.

The cheapest - 135.7 cents a litre - was at the Metro Petroleum station at Berkeley.

The most expensive regular unleaded fuel was at the Thirroul Caltex, where the price board read 153.9 cents.

That's a price variation of 18.2 cents and an indication of the money that can be saved by shopping around.