Oil prices -- a major component of gasoline costs -- remain well below their July record high, but energy experts said that won't translate immediately into lower pump prices for consumers.
Crude oil has been accounting for about 70 percent of the cost of a gallon of gasoline, said Doug MacIntyre, a senior oil market analyst with the U.S. Energy Information Administration.
However, gas prices also are determined by several other factors, including refining, distribution and marketing costs, profit margins and state and federal taxes, he said.
"Normally you would expect 70 percent of the crude-price drop to be reflected in the retail (price of gas)," MacIntyre said. "But we haven't quite seen even that much yet because you really also need to look at the two main markets that drive retail prices -- that's the crude-oil market, but also the U.S. retail market."
A number of U.S. Gulf Coast refinery operations were shut down this year by hurricanes Ike and Gustav, leading to limited supplies and spot shortages that held a firm grip on retail gas prices, including those in the Southeast, he said.
That mitigated the impact of lower oil prices on retail gas prices, MacIntyre said. But as refinery operations return to normal, lower crude prices will have more of a pronounced impact, he said.
"We're starting to see retail (gas) prices drop faster than crude," he said. "So the drop is catching up and probably sometime over the next several weeks, we will see gasoline prices down as much as crude oil prices have come down. It was a little bit delayed because of all the refining issues stemming from the hurricanes."
Light, sweet crude for November delivery rose $2 Friday to settle at $71.85 a barrel on the New York Mercantile Exchange. Oil is now down $75 -- or 51 percent -- since catapulting to a record high of $147.27 on July 11.
In South Carolina, a gallon of regular unleaded gasoline was $2.957, down from $4.075 a month earlier but higher than $2.641 a year ago, when oil was between $86 and $89 a barrel, according to AAA and the EIA.
The movement of oil prices "certainly should impact" the cost of gasoline, said David Bodde, a senior fellow at Clemson University's Spiro Institute for Entrepreneurial Leadership and an expert in energy policy.
However, "this absolutely amazes me," said Bodde, who studied oil markets for 30 years.
"What this plunge in price suggests to me is that the fundamentals of supply and demand are perhaps a secondary consideration in this (world oil) market," he said.
"If, at 140 (dollars) a barrel, this was a supply-and-demand driven phenomena, we've only seen a small pullback in demand -- a few percentage points," he said.
Demand for gasoline over the four weeks ended Oct. 10 was 5.2 percent lower than a year earlier, according to the EIA.
On the East Coast, gas stations pay about the same price for refined gas, said Brandon Wright, a spokesman for the Petroleum Marketers Association of America, a trade group.
When they pay higher wholesale costs because of increases in crude oil prices, nearly all gas station operators will increase their retail prices, with a relatively small markup on what they sell, he said.
Competition is what forces retailers to reduce their pump prices when crude oil falls because of the fear of losing market share, he said.
"It's an extremely competitive industry," Wright said.
The U.S. Government Accountability Office, the investigative arm of Congress, said in a report last year that the price of crude oil is just one of a number of factors that affect gasoline prices.
Others include demand, U.S. refinery capacity, gasoline inventories and regulatory factors, such as national air quality standards, GAO officials said.
In testimony before a House Energy and Commerce subcommittee, Thomas McCool, the GAO's director of applied research and methods, said it "can be daunting" for the average person to understand how the oil industry, consumers and the government interact to influence gas prices.
"Gasoline prices are affected by the decisions of the industry regarding refining capacity and utilization, gasoline inventories, as well as changes in industry structure such as consolidations; by consumers' decisions regarding the kinds of automobiles they purchase; and by government's regulatory standards," McCool said.
