THE cost of petrol in New South Wales is about to take its biggest quarterly hike in 25 years after about seven months of lower prices.

The NRMA has warned drivers to fill their tanks to avoid a price spike of 17c to $1.50 a litre expected by Friday.

It will be the highest average price since October, despite an overall state-wide reduction over the past fortnight.

Prices have already started to creep up on the North and Mid North Coasts ahead of the predicted surge.

Coffs Harbour unleaded prices jumped 1.7c from June 7 to 14 to reach $1.38 a litre.

Woolgoolga drivers were charged 3.1c more over the same period to hit an average of 146.9c over the past week.

Casino remained the third cheapest town in the state with unleaded petrol costing $132.8c. 

BOWSER BUSTERS

Average unleaded prices for week ending June 14

Casino - 132.8c

Grafton - 134.4c

Lismore - 135.2c

Sydney - 137.8c

Coffs Harbour - 138c

Ballina - 141.6c

Murwillumbah - 144.4c

Tweed Heads South - 145.4c

Canberra - 144.5c

Woolgoolga - 146.9c