That’s the finding of a report from the consumer watchdog today, which shows the full benefits of low oil prices are not being passed on to motorists.

International crude oil and refined petrol prices fell to their lowest levels in more than a decade, partly thanks to a global oil production glut.

But while average petrol prices in 2015/16 fell to their lowest levels since 2002, retail margins jumped to their highest levels since Australian Competition and Consumer Commission records began in 2002.

ACCC chairman Rod Sims said he was concerned about the petrol industry’s high margins.

“This report suggests that in order for there to be more competitive pressure on retailers, consumers need to shop around and reward those offering the best-priced fuel,” he said.

The report found average petrol prices in the five largest capital cities – Sydney, Melbourne, Brisbane, Adelaide and Perth – jumped seven cents a litre in the June quarter.

The average price was 121.7 cents per litre in 2015/16.

The international refined petrol price accounted for 51 cents, taxes another 50.4 cents while wholesale and retail costs and margins made up 20.3 cents.

The report says major retailers blamed the increased margins on higher operating costs, including biofuel mandates in NSW and Queensland.

Of the five largest cities, prices were highest in Brisbane, with the ACCC blaming a lack of competition.

Meanwhile, petrol prices in Hobart and Canberra were always higher than the five major cities throughout 2015/16.

Average petrol prices in 2015/16:

• Adelaide: 120.3 cents per litre
• Sydney: 120.8 cents
• Melbourne: 120.8 cents
• Perth: 122.0 cents
• Darwin: 124.4 cents
• Brisbane: 124.7 cents
• Canberra: 126.9 cents
• Hobart: 130.2 cents

-AAP