Gas prices tick higher
Average price of unleaded rises to $1.673, according to AAA survey.
NEW YORK (CNNMoney.com) -- Gasoline prices increased for the fourth day in a row Friday, according to a daily survey of gas station credit card swipes.
The price of regular unleaded rose 0.3 cents to a national average of $1.6730 a gallon from $1.67 on Thursday, according to motorist group AAA.
Average gas prices ticked higher on Saturday for the first time in nearly three months, according to AAA. They briefly retreated for one day before resuming their upward climb.
The price of gasoline has fallen in tandem with the price of crude oil, which has shed more than $100 a barrel since July. Oil demand has declined rapidly as the world economy has slowed.
According to the Transportation Department, Americans drove 100 billion fewer miles between November 2007 and October 2008, compared with a year earlier.
Local prices: Gas is currently selling below $2 a gallon in nearly all states, with the exception of Alaska, where gas prices averaged $2.648 a gallon, and Hawaii, where gas was $2.402 on average.
Gas was cheapest on average in Wyoming, at $1.477 a gallon, according to AAA. Missouri, the first state to see average prices drop below $1.50 a gallon, saw prices bounce back above that mark on Friday to $1.513.
Out of major U.S. cities, Anchorage, Alaska, has the highest average gas prices, at $2.404 a gallon, according to GasBuddy.com, a service that lets motorists post local fuel prices online. Salt Lake City, Utah, had the lowest average, at $1.383.
Diesel: The price of diesel fuel, which is used in most trucks and commercial vehicles, fell Friday by 1 cent to a national average of $2.519 a gallon, according to AAA.
Diesel prices have fallen more than $2 a gallon since hitting a record high of $4.845 on July 17.
Ethanol: The price of E85, an 85% ethanol blend made primarily from corn, fell by nearly a penny to an average of $1.499 a gallon in Friday's survey, according to AAA.
E85 can be used in place of regular gas in specially configured "flex-fuel" vehicles, but it is not readily available in some states.
The AAA figures are state-wide averages based on credit card swipes at up to 100,000 service stations across the nation. GasBuddy prices are averages of local regular unleaded gasoline prices that about 700,000 volunteer gas prices spotters have posted online. Individual drivers may see lower fuel prices in different areas of each state.
CNNMoney.com staff writer Kenneth Musante contributed to this report. 
