Average gasoline prices declined in 48 states over the last week, while diesel prices fell in 46 states. However, Gas Buddy says that relief may be short-lived. Oil prices surged in Sunday night trading after Iran re-closed the Strait of Hormuz and President Trump signaled further escalation if Tehran does not come to an agreement. As a result, gas prices are likely to rise again in the coming days. Average gasoline prices in Minnesota have fallen 8.0 cents per gallon in the last week, averaging $3.66. The national average price of gasoline has fallen 9.4 cents per gallon in the last week, averaging $3.97. The national average price of diesel has decreased 11.7 cents compared to a week ago and stands at $5.50.