Why does the petrol price frequently peak on the same days each week?
The price of petrol generally goes up on the same day each week because of competitive discounting over the previous week. Because discounting increases sales for a short period until competitors react, some service stations will continually move prices downwards in small steps. It takes about a week to reach the point where petrol is being sold close to or below cost, which is unsustainable. Consequently, at different times on Wednesday or sometimes Thursday, other petrol retailers independently increase their prices at some or all of the sites where they control the price. Competitors are carefully watched and if their prices don’t increase to similar levels, retailers may reconsider their price increases. Price increases are not timed to coincide with pension or pay day.
