ACCC Chairman Rod Sims says margins being charged by petrol retailers are costing consumers hundreds of millions of dollars, as the average price of fuel reaches a four year high.

The cost of unleaded petrol is almost 12 per cent higher than it was this time last year, with major cities including Sydney, Melbourne, Brisbane and Perth seeing an average price of $1.45 per litre.

The price of international crude oil, set by the Organization of the Petroleum Exporting Countries (OPEC), is being blamed for the spike in price.

Mr Sims says the weaker Australian dollar also hasn’t helped local consumers, but some petrol retailers are making use of margins and it’s costing motorists big time.

“There’s no doubt there’s two or three cents where retailers are charging more than they should and that’s costing motorists real money,” he tells Ross Greenwood.

“Two to three cents is $400-600 million across the Australian economy so we’re talking about real money.”

When asked whether the market is lacking competition, Mr Sims says in some cities that’s the case, with Brisbane being hit the hardest.

The ACCC Chairman says the price disparity in major cities is severe and consumers need to do their research before heading to the bowser.

“Right now, Ross, in all the capital cities, the gap between the highest and lowest is about 20 cents a litre.

“A little bit of extra effort can save you a lot of money at the petrol pump.”

Click PLAY below for the full interview