American drivers have paid an additional $8.4 billion in fuel costs since the Iran war started, according to a new estimate from the Joint Economic Committee’s Democratic minority. 

The lawmakers’ calculation is based on daily average gasoline prices as tracked by AAA between Feb. 28, when the U.S. and Israel attacked Iran, through March 31. The figure also draws on information from auto researcher Edmunds on the tank sizes of top-selling gas vehicles in the U.S. and on federal fuel consumption data from the Federal Highway Administration and Energy Information Administration.

The average cost of gas across the U.S. rose to $4.06 a gallon on Wednesday after topping $4 the previous day for the first time since 2022, according to AAA data.

Drivers of Toyota RAV4s now spend $58.26 to fill up their tanks, an increase of $15.02, or 35%, from before the war, the analysis finds. A Ford F-150 pickup truck costs $144.65 to fill up, an increase of $37.29, while Toyota Camry sedan owners are spending $52.23 to fill their tank, or $13.46 more than before the conflict started last month.  

Despite higher gas prices in March, credit card data shows consumers are continuing to spend, suggesting households so far are weathering the financial impact of higher fuel costs, according to Navy Federal Credit Union. 

But the Conference Board Consumer Confidence Index, released on March 31, shows fewer Americans are planning big-ticket purchases over the next six months, a sign some households could be feeling the effects of higher fuel costs.

“The strain is starting to show, especially as gas hits $4 a gallon nationwide,” said Heather Long, chief economist at Navy Federal Credit Union, in an email. “It’s almost certainly going to be a muted second quarter for spending and GDP growth as the worst of the inflation shock hits consumers.”

The White House didn’t immediately respond to a request for comment.

The Trump administration has said that the recent spike in gas prices is temporary and that fuel costs will subside when the Iran war ends.

“When Operation Epic Fury is complete, gas prices will plummet back to the multi-year lows American drivers enjoyed before these short-term disruptions,” White House spokeswoman Karoline Leavitt told CBS News in an email on Tuesday. 

A recent CBS News poll of  3,335 adults found that rising gas prices are heightening concerns about the U.S. economy. 

About one-third of Americans are making changes to their spending or savings habits to cope with higher gas prices, while another 35% said they plan to adjust their budgets if fuel costs remain elevated, according to a new LendingTree study. 

Texas and California residents have faced the sharpest increase in gas costs due to their large populations and number of drivers. Texans have paid an additional $1.04 billion in fuel costs since Feb. 28, while Californians have paid an extra $970 million at the pump over the same time, the JEC Minority report estimates. 

Other states with significant increases include Florida, with $684 million in extra gas costs, and North Carolina, with an extra $361 million in spending, the analysis said.