Gas prices in the state of Illinois have continued their decline into September.
GasBuddy's head of petroleum analysis, Patrick De Haan, thinks that prices at the pump will continue to fall as the winter months are ahead
According to GasBuddy price reports, average gasoline costs in Illinois dipped under $4.00 this week. De Haan notes diesel prices have dropped only half as much as gasoline, and he reasons that due to supply and demand issues.