Petrol prices on the rise in SA after weeks of lower costs

Petrol prices could be about to go up for the first time in more than 60 days in South Australia, with some service stations charging more than 10 cents a litre on previous low prices.

Chris West, a senior analyst with the RAA, told 891 ABC Adelaide while there were some service stations selling petrol as low as $1.05, about 40 per cent of sites had moved to increase their prices to $1.16 a litre since Sunday.

"It is definitely time to be filling up, because there's no knowing where this price is going to go," Mr West said.

He said the price fluctuation was part of the fuel cycle for Adelaide.

"The oil price is affecting the cost price. That cost price has fallen down to that dollar marker and as part of the fuel cycle we typically see retailers move towards cost price before they start to spike," he said.

"So in this case we've had quite a few $1.02s around Adelaide over the last week, but it is unfortunately the situation where retailers have had a very thin margin for a long time.

"We haven't seen a fuel increase for 68 days ... we realised at some stage retailers would try to move this price, so it seemed to be Saturday night, Sunday morning there was at least one major brand that tried and at this stage we're still advising people to fill up."

Mr West said at the beginning of the fuel cycle South Australian motorists were paying up to $1.50 per litre.

"We have had almost a 50 cent drop in this current fuel cycle. It's come down a long way," he said.

"At this stage oil costs have stabilised, so this next fuel cycle, we could well see prices head towards that dollar marker all over again."

Mr West said he could not rule out petrol dropping below $1 a litre in coming weeks.

"We have one service station at Kilburn at 99 cents," he said.

"Given that we have the Australia Day long weekend, a retailer may try to offer a promotional price and we may see cheaper prices, but we'll just have to wait and see."