BLOOMINGTON - Past hurricane activity and fear of damage that still may come are keeping gasoline prices high even as the cost of a barrel of oil drops. When the price for a gallon of gasoline made its historic march higher and higher throughout the first half of the year, industry analysts pointed to the simultaneous climb of a barrel of oil as the culprit. | National gas prices spike | Video: Ike approaches | Find the best gas prices in Central Illinois

But as the cost of a barrel of oil falls closer to $100, the price for a gallon of regular gasoline jumped about a quarter to $3.88 in the Twin Cities this week.

Oil's fall from a record $147.27 to Wednesday's price of $102.58 is a 30 percent drop. By comparison, gasoline's drop from a national high of $4.114 to $3.668 is an 11 percent drop. When a barrel of oil crossed the $100-mark for the first time in February, the average cost of a gallon of gasoline was $3.12 nationwide and $3.19 in Bloomington-Normal.

The national average cost per gallon was $3.67 overnight Wednesday, up slightly from $3.65 the day before, according to AAA-Chicago. Elsewhere in Central Illinois, the cost per gallon jumped from about $3.55 to from $3.87 to $3.99 a gallon in Springfield, according to www.gasbuddy.com. In Decatur, gas prices ranged from $3.57 to $3.69 Wednesday.

The cost for oil is the main factor that influences pump prices, but it's not the only one, said Nicole Niemi, spokeswoman for AAA-Chicago Motor Club. Hurricanes, refinery issues and lower production levels also play a role, she said.

"Gasoline and oil prices don't always move in tandem," Niemi said. "There's just too many factors."

When oil reached its peak of $147 a barrel in July, gasoline prices did not go as high as they should have in a strictly oil and gasoline equation, Niemi said. Gas prices could have reached $4.50, but instead settled at a national high of $4.11 as people took steps to conserve fuel, she said.

The main reasons for the recent spike in gasoline prices are refinery issues related to Hurricane Gustav's landfall in the Gulf Coast last week and other regular maintenance work, Niemi said. Even though hurricane damage was not as severe as forecasted, refineries still shut down production, and it takes time to get back online, she said.

Inventory fell to 78 percent of U.S. refineries' capacity last week, according to the U.S. Energy Information Administration in Washington D.C. Usually, sites run at 90 percent capacity and rarely fall below 85 percent, Niemi said.

"With Hurricane Ike heading toward Texas, it's possible there could be more shutdowns at refineries, which would decrease output," she said.

Oil prices fell on news that Hurricane Ike might not hit areas of the Gulf Coast with major refineries, but wholesale gasoline prices did not follow the same path, said Bill Fleischli, executive vice president of Illinois Petroleum Marketers Association in Springfield.

Wholesale gasoline markets reacted to the fear that the storm still could hit the U.S., Fleischli said.

"The hurricane drove them up," he said.

Wholesale gasoline prices in the Midwest also are about 30 to 50 cents higher than the rest of the country because of some refinery issues in that area, Fleischli said.

The possibility that OPEC could significantly cut production by 520,000 barrels a day also could negatively impact gasoline prices since the supply would be lower, experts said.