Gas prices continue decline
The nationwide price at the pump falls to $3.672 a gallon, down nearly a penny.
NEW YORK (CNNMoney.com) -- Gasoline prices fell slightly Tuesday, bringing the total decline in the nationwide average to more than 10% since mid-July, according to a daily survey of gas station credit card swipes.
The price of regular unleaded gasoline fell nearly a penny to $3.672 from $3.681 a gallon a day before, according to AAA and the Oil Price Information Service.
Gasoline prices have fallen more than 44 cents since hitting an average high of $4.114 a gallon on July 17th.
The decline in gas prices has followed a sharp drop in the price of crude oil.
Crude on the open market has fallen more than 20% since hitting a high of $147.27 in July as investors worried that high fuel prices were causing people to cut back on consumption.
Worries about demand have helped push gasoline prices below $4 a gallon across the continental United States. Prices remain the highest in Alaska, at $4.577 a gallon, followed by Hawaii, at $4.399.
The lowest gas prices continued to be in Missouri, at $3.427 a gallon.
Gas prices at the pump tend to be cheaper in states close to the nation's oil and refining infrastructure such as those near the Gulf of Mexico, and in states with lower gasoline taxes, such as Missouri or New Jersey, which have some of the lowest rates.
Despite the nationwide gas price having fallen for more than a month, prices remain more than 90 cents above where they were 12 months ago.
Ethanol: The price of E85, an 85% ethanol blend that can substitute for gas in specially configured "flex-fuel" vehicles, rose to $3.045 a gallon on average from $3.035, AAA reported.
The link between volatile crude prices and retail gas prices has caused many Americans to pay more attention to E85, which is made primarily from corn.
However, while ethanol is made from renewable sources, it's difficult to find outside the corn-producing midwest region, and it's not sold in some states.
And while it's cheaper than petroleum-based fuels, it also generally burns less efficiently than gasoline in flex-fuel vehicles. Drivers would have to pay the equivalent of $4.007 a gallon for E85 to get the same mileage as gasoline, AAA estimated.
Diesel: Diesel, which is used to fuel most trucks and commercial vehicles, fell to $4.283 from $4.291 a day before.
Because of its use in shipping and transportation, high diesel prices can drive up costs for businesses, which can hike the cost of other goods as they pass those costs off to customers.
Diesel fuel prices have also fallen since July, but remain more than $1.36 higher than they were a year ago.
Diesel prices were most expensive in Hawaii at $5.306 a gallon and Alaska at $5.149. Prices were cheapest in Missouri at $4.029 a gallon. 
