The increase is due to two drone attacks on Saudi Arabian oil fields affecting production.

Royal Automobile Club of Tasmania general manager of mobility services Darren Moody said it was difficult to predict how much prices would rise.

"We estimate it will rise between eight and 14 cents a litre in less than two weeks," Mr Moody said.

"The price for premium petrol is already close to $1.80 a litre and we soon might see it get close to $2 a litre."

Mr Moody said the last increase at the bowser was earlier this year when prices jumped from about $1.30 to $1.45 a litre.

"It seems to be a bit cheaper on the North West Coast and that's probably because of healthy competition," he said.

The RACT urges motorists to shop around for the best prices.

"The biggest influence on fuel consumption seems to be shop around and try to reduce fuel consumption is driver behaviour," Mr Moody said.

"People should drive at a reasonable speed and drive smoothly to reduce consumption.

"If your golf clubs are in the boot, take them out and reduce the weight in your vehicle."

Mr Moody said petrol prices in 2009 and had risen as high as $1.80 for regular unleaded petrol.

He predicted higher prices would be here for a while yet.

"What we're seeing will be with us for the next six months," Mr Moody said.

"The key is to get the fire out, get it repaired and start production."

Tasmanian Automobile Chamber of Commerce general manager Malcolm Little said history showed that any interruption to world supplies affected prices.

"There can be a knee jerk reaction but we are not going to run out tomorrow or have a lack of supply in the next few months," Mr Little said.

Mr Little estimated a rise of 10 cents a litre was on the cards.

"There will probably be a 15 per cent increase for oil and petrol but that will be on the real price of 70 to 80 cents a litre not the bowser price," he said.

"The real winners are the government because 65 cents of what you pay goes in taxes and excise.

"Retailers won't push up the price immediately and may decide to absorb it for a period of time."

Mr Little said Tasmanian motorists should be concerned about threats against Iran by United States president Donald Trump.

Federal Minister for Energy Angus Taylor condemned the attacks and said there was no immediate threat to Australia's fuel supplies.

He said the government was told there were "ample commercial stocks globally".