Karen Smoak only fills half the gas tank of her Honda Odyssey these days.
"Prices are fluctuating so much lately. You never know when it might go down a few cents somewhere just a day after you fill up," she said as she pumped gas Tuesday at the RaceWay on Broad Street.
The mother of five makes a daily trek from the family's Soddy-Daisy home to Chattanooga, where her kids attend school, so every cent counts.
The recent seesawing of prices at the pump has plenty of motorists besides Smoak keeping a watchful eye on their pennies.
"We'll see a dip, but then a week later we'll have another markup," said AAA spokeswoman Jessica Brady. "It's been hard to make any substantial predictions about what's in store."
The latest readings show a drop. After a government report gave strong evidence that higher pump prices are forcing Americans to drive less, gasoline futures fell almost 8 percent Wednesday, tipping oil back below the $100-a barrel mark, The Associated Press reported.
In Chattanooga, gas price averages fell 1 cent Wednesday from last week, according to the AAA Fuel Gauge Report.
But prices are still up 13 cents from a month ago and up a dollar from where they were a year ago, the report shows. A year ago, it cost Smoak about $50 to fill up her van. It's now pushing $70.
On the other hand, the AP reported Monday that prices likely would drop at least 50 cents a gallon within a few weeks.
Who's right? It's hard to tell, said Dr. Ziad Keilany, professor of economics at the University of Tennessee at Chattanooga.
"This is a tricky year because the economy hasn't made a full-force recovery yet," said Keilany. "If we are in a full-fledged recovery, prices will keep going up. But we don't know if we're fully recovering yet."
On top of economic uncertainties are dozens of other factors that stymie economists' efforts to make firm predictions: uprisings in the Middle East, hurricane season beginning to churn and most recently, flooding along the Mississippi.
"The market is reacting event by event, economic report by economic report. So at any moment, the market could shift," Brady said.
Brady said any summer drop likely won't last long.
"Until there's some consistent trending in terms of the barrel price, we won't really see prices drop off in a substantial way," Brady said.
In the long run, Keilany thinks prices will continue to climb.
"The economy seems to be perking up," Keilany said. "Chances are that demand will rise, which means prices will follow suit."
Brady said surveys are still out about how many people will hit the road for vacation this summer.
"You could still see people traveling, though it could be closer to home or to places where they can stay with family," she said.
For now, Smoak said her family still plans to make a beach trip this summer.
"We'll find other ways to cut down on costs," she said.