The price of gasoline continues to rise across the US. The national average price of regular unleaded gasoline was $3.156 a gallon today , up about three cents from $3.127 recorded last Friday, according to AAA Fuel Gauge Survey. The average price of diesel fuel has climbed to $3.548 a gallon, up from $3.516 last week.

Wyoming, Missouri and South Carolina are the only 3 states left with gas prices averaging below $3.

Despite crude oil prices falling in recent days, US prices continue to climb. The current price of crude oil is hovering in the mid $80 a barrel range.

At first blush, world oil prices don’t seem to explain why U.S. gas prices are so high and going higher. After all, the price of crude oil has dipped in recent days, and is hovering now in the mid $80 a barrel range.

Apparently there is more than one oil price gauge gas prices. Oil solid on the Nymex Exchange in New York is about $85 a barrel, but Brent crude, the European oil standard, is selling at $105 a barrel,  a $20 difference. U.S. refineries are using the more expensive Brent crude to produce gasoline, while the cheaper crude oil is being stored in reserves.

According to current the Nymex Exchange in New York, Brent crude prices are much higher due to unrest in the Mideast and the Saudi Arabia’s reluctance to increase oil production. If the U.S. refineries rely on Brent crude, American drivers will pay a higher price for gasoline.

The good news is U.S. energy supplies remain ample. The US Energy Information Administration reports stockpiles of crude oil rose by 900,000 barrels in the week ending Feb. 11, while gasoline supplies increased by 200,000 barrels.