ISLAMABAD: The federal government has revised the mechanism for determining petrol prices amid volatility caused by the Iran-US war, changing how imported and locally refined petrol will be priced.The federal cabinet approved the revised mechanism on October 30, according to Petroleum Division documents.The changes apply specifically to Motor Spirit (MS), or petrol, while all other parameters for petroleum product pricing will remain unchanged.Under the revised formula, the import price of petrol will be determined on the basis of the actual import cost of the relevant Pakistan State Oil (PSO) cargo.If the actual import cost is unavailable for daily pricing, the premium, incidentals and customs duty of the last available cargo will be used to determine the import price.The change modifies the mechanism introduced earlier this year under which petrol prices were determined using PSO import data and different averaging arrangements.The government has also introduced a temporary mechanism for local refineries for the next 30 days.During this period, the premium, incidentals and customs duty used to calculate the ex-refinery price of petrol will be fixed at the levels effective on March 7, 2026 — before the Iran-US war.