Gas prices are at an all time high for this time of year.
The average price for a gallon of regular is $3.56, and it's eating into monthly budgets.
Experts say growing global demand, supply issues due to refinery problems on the East Coast and ongoing conflicts in oil rich countries.
"The geopolitics in the Middle East causing a psychology of fear about future supply has probably never been greater," says former Shell Oil CEO John Hofmeister. "We just don't know from week to week how bad it could get."
Iran doesn't sell oil to the U.S., but their move to cut off supplies to France and Britain this summer could cause the European countries to turn to U.S. suppliers.
That could drive prices to four dollars and beyond by Memorial Day.
"Americans feel sick to their stomach when they see that and it impacts the purchases that they make," says GasBuddy.com senior petroleum analyst Patrick DeHaan. "So if gas prices go up even further it's likely that we will see a dent in the economy"
Some consumers are already making adjustments, thinking twice and cutting back where they can.