Some analysts say the variation in petrol prices in Sydney across the week, which can be as much as 13 cents per litre for standard unleaded, is proof the market is completely transparent, so retailers can see very easily, from price boards or online prices, what the competition is charging and respond with lower or higher prices. Others say it is evidence of collusion on prices.

To view the data on price difference before and after the announcement of the ACCC inquiry into fuel prices, click here.

What do you think?