Costco thinks the Energy Board is making errors when it calculates operating costs for gas stations.
In a bid to slash the price at the pumps, Costco is disputing how the board calculates the costs incurred by stations every week in the province.
Last year, a decision increased the amount used in a calculation from 3 to 3.5 cents per litre sold.
Costco is arguing that the operating costs are heading down thanks to market competition, as well as increased efficiencies in business models, according to a report in the Journal de Montreal.
The retailer wants to see that 3.5-cent figure reduced to 2 cents.
The report also said stations profit from volume rebates.