Motorists in Adelaide are being urged to fill up on fuel as quick as possible with prices about to spike.

The Royal Automobile Association (RAA) thought prices would surge overnight, but they have remained steady today.

“Certainly the spike is overdue, we would have expected the spike to have been in our market since Tuesday,” said Chris West from the RAA.

“It is welcome relief though for motorists, so if you haven’t taken advantage of the low prices, make sure you fill up.”

Fuel prices have been hovering around the low $1.30s all week, a trend the RAA expects will end soon.

“Today we have seen prices fall to $1.34, there are prices as low as $1.31, if you haven’t already done so, we encourage you to fill up,” Mr West said.

“At this stage we would expect a spike of around that $1.50 mark, we have seen similar spikes interstate, only in the last couple of days.”