California’s fuel price record could be broken this weekend, with more than \$5 (£3.09) a gallon being charged in some parts of the state.
The average statewide price of regular petrol hit a record high of \$4.61 (£2.85) per gallon in June 2008, a figure which has now been equalled, but even that is likely to be surpassed within the next few days.
The average price stood at \$4.49 (£2.78) on Friday - up 32 cents (20 pence) from a week ago - and prices are expected to continue to rise.
One station in Calabasas, outside Los Angeles, was charging \$5.69 (£3.52). The national average is about \$3.79 (£2.34) a gallon.
The state has overtaken Hawaii as the state with the most expensive fuel, according to AAA’s Daily Fuel Gauge report .
Analysts say refinery and transportation problems are behind the wholesale price rises.
A state pollution law meaning that a special type of cleaner-burning petrol must be sold between April to October has added to the expense.
The California Air Resources Board says it is reviewing a request from the California Independent Oil Marketers Association to allow petrol stations to begin selling winter-blend petrol earlier.
State officials said consumers should see prices fall some time during the next week.
"The wholesale market appears to have peaked and is heading down," said a spokeswoman for the California Energy Commission .
She added: "Because it takes a little while for the price reductions to funnel through the system, consumers at the pumps should start to see some declines over the next week."
Some petrol stations have closed rather than pay the increased costs to refill their fuel stocks and risk losing money when prices fall.
The price of diesel fuel has also increased to \$4.48 (£2.77) per gallon on average across the state, up 35 cents (22 pence) from a year ago.