The national average price of regular gasoline reached $4.003 a gallon Monday, up 13 cents in one week.
Renewed fighting between the U.S. and Iran has pushed oil prices higher and raised concerns about supplies moving through the Strait of Hormuz.
Gasoline now costs about 86 cents a gallon more than it did a year ago, adding roughly $13 to the cost of filling a 15-gallon tank.
Amid new fighting in the Middle East, the national average price of gasoline has risen sharply over the past week, and further increases may depend on how long the fighting continues.
The national average price of regular gas crossed the $4 mark again on Monday, reversing some of the relief drivers received earlier this summer.
The national average price of regular gasoline reached $4.003 a gallon Monday, according to AAA’s daily fuel-price survey. That was up from $3.998 Sunday, $3.872 a week ago, and $3.951 a month ago.
The increase is even more striking compared with last summer. The national average stood at $3.141 a gallon one year ago, meaning consumers are now paying about 86 cents more for every gallon they buy.
For someone filling a 15-gallon tank, that year-over-year difference adds nearly $13 to the cost of a fill-up.
Middle East conflict drives oil higher
The latest increase at the pump is largely tied to renewed hostilities between the United States and Iran. The fighting has pushed crude-oil prices higher and renewed concerns about possible disruptions to shipments through the Strait of Hormuz, a critical route for global energy supplies.
Brent crude, the international benchmark, rose to nearly $91 a barrel Monday, while U.S. benchmark crude climbed to about $84.
AAA had warned last week that instability around the Strait of Hormuz was already contributing to higher pump prices. At that time, the national average had risen 10 cents in a week to $3.94.
Prices at the pump often lag behind changes in crude oil and wholesale gasoline markets. That means some service stations may continue raising prices even if oil prices stabilize in the short term.
Prices vary widely by state
Although the national average has reached $4, drivers’ experiences differ considerably depending on where they live.
AAA reported Monday that California had the nation’s highest state average at nearly $5.50 a gallon. Hawaii averaged about $5.42, Washington was just over $5, and Alaska stood at approximately $4.66.
At the other end of the scale, Indiana had the lowest average at about $3.35. Mississippi, Texas, Louisiana, and Oklahoma were all averaging less than $3.60.
State taxes, environmental fuel requirements, refinery access, and transportation costs all contribute to regional price differences.
Diesel prices are also elevated. AAA put the national diesel average at $5.108 a gallon, up from $4.875 a week ago and $3.727 one year ago. Higher diesel costs can eventually affect prices for groceries and other merchandise because most consumer goods spend at least part of their journey on a truck.
Where prices go from here
The immediate direction of gasoline prices will likely depend on oil markets and the conflict involving Iran. A diplomatic breakthrough or easing of hostilities could send crude prices lower, eventually providing relief at the pump.
Further escalation — especially anything that restricts oil-tanker traffic through the Strait of Hormuz — could cause another sharp increase.
Consumers can limit some of the impact by comparing prices before filling up, combining errands and avoiding aggressive acceleration. Drivers should also check tire pressure because under-inflated tires reduce fuel economy.