Petrol companies have been accused of ripping off NSW motorists after fuel ­prices jumped more than 10 per cent over the past week.

The staggering increases have come at the worst possible time for many families who are still on the summer holidays or returning from Christmas and new year trips.

The price of E10 ethanol fuel, which the state government has controversially forced larger retailers to sell more of — despite the persistent unpopularity of the fuel — has jumped 14 per cent across the state since January 3.

The average price of E10 was $1.38 per litre on Tuesday, up from $1.21 on January 3.

Unleaded 91 rocketed 10 per cent over the same period, going from $1.25 a litre to $1.38.

The rises have been mirrored in other types of fuels.

Better Regulation Minister Victor Dominello urged motorists to shop around by using comparison websites to avoid being “ripped off”.

The government runs its Fuel Check website, while the NRMA runs a comparison app with real-time data on individual servos.

“The new year has delivered more pain at the pump for motorists, with petrol prices increasing across the board over the past week,” Mr Dominello said.

Mark McKenzie, boss of the Australasian Convenience & Petroleum Marketers Association, said price rises were partly driven by production cuts agreed by oil cartel OPEC in December, which initially forced oil prices up.

He denied the price spikes were designed to gouge customers on their holidays, a claim borne out by Australian Competition and Consumer Commission research.

He said the rises were also part of the petrol price cycle, with spikes ­occurring after ­periods of ­discounting.

University of Sydney economist Nicholas de Roos said the cycles were unrelated to cost and demand conditions.

“I doubt it is related to the holiday period in particular,” he said. “The ACCC has investigated this issue a number of times … and identified no role for public holidays in retail pricing.”

NRMA spokesman Peter Khoury said independent petrol stations were consistently cheaper than larger chain retailers, with some major chains making huge profits. “But prices went up demonstrably higher than they should have,” Mr Khoury said. “I think what has happened is the major chains have used OPEC as an excuse to put their prices up.”

Extracted from Herald Sun.