Yes, Petrol station dealers do not dictate the stock levels. It's done centrally by the petrol company - and all fuel sold by the petrol company to the dealers are done in cash/cheque immediately upon delivery. So for example a tanker comes with 20,000 liters of RON95 fuel, they need to immediately pay RM37,162 - Retail price is RM39,600, but it can be as low as RM39,204 if everyone is paying via credit card. Petrol dealers need rolling cash as well, because the credit card companies generally disburse the funds to them around 3 working days after the consumer swiped the card

Basically, the Petrol companies get their profit immediately upon selling the petrol to the dealers, but dealers will only get the profit once consumers buy the petrol from them So you can see the petrol companies have the upper hand when they themselves control the stock levels for all dealers, and the dealers are at the mercy of both the consumers and petrol companies.