Why don't fuel prices always strictly follow global oil prices?

Post No. 464. Fuel prices do not depend solely on the global prices of crude oil. They also reflect the cost of its refinement into petrol, diesel or kerosene, as well as the specific supply and demand conditions for each refined product. When the supply of refined products is constrained by external factors, fuel prices may therefore remain high, or even rise, without a corresponding change in the price of crude oil.