When I worked at a gas station as a teenager there was definitely an unspoken implicit agreement that the price of gas would be 6 cents/liter above wholesale IIRC. Which was highly competitive and didn't completely cover costs.
Huh? I can go to most any gas station-occupied intersection and you will always find two that match and one (usually a Persian-owned Chevron) which is consistently a dollar or more higher per gallon across all grades of fuel.