Gas prices down another penny
AAA's daily survey falls for 31st straight day, bringing the total decline to more than 36 cents a gallon
NEW YORK (CNNMoney.com) -- Gasoline prices fell Sunday for the 31st straight day, bringing down the nationwide average in a motorist group survey by more than 36 cents overall.
The price of regular unleaded gasoline at the pump fell 1 cent to $3.751 a gallon, according to the Daily Fuel Gauge Report from motorist advocacy group AAA and the Oil Price Information Service. The average is based on credit card swipes at 100,000 service stations.
Prices have fallen 8.8% since hitting a record high of $4.114 a gallon on July 16,. The decline has come in the wake of a 22.7% drop in crude futures from their peak last month.
Gas prices remained about 99 cents, or 35.8%, higher than a year ago.
State prices: Gasoline exceeded $4 a galllon in five states, all in the West, according to the survey. Alaska had the highest prices at $4.559 a gallon, up 0.2 cent from the previous day. Hawaii was second at $4.432, followed by California at $4.051, Utah at $4.047 and Idaho at $4.018.
Missouri had the cheapest gas, with prices falling 0.6 cent to $3.514 a gallon. Prices in South Carolina were the second lowest at $3.531, followed by Oklahoma at $3.539, Tennessee at $3.558 and Arkansas at $3.574.
Ethanol: The price of E85, an 85% blend of corn-derived ethanol available to some vehicles, rose to $3.052 a gallon on average from $3.044, AAA reported.
Ethanol burns cleaner than gasoline but has a lower energy content and burns less efficiently in flex fuel vehicles. According to AAA's estimates, a vehicle that burns E85 would pay $4.016 a gallon to get the same mileage as gas.
Diesel: The average price for diesel fuel, which is used in most trucks and commercial vehicles, fell more than 1.5 cents to $4.406 a gallon from $4.421 the day before, according to AAA.
The price of diesel has risen 50.6% over the past 12 months. Because of its use in transporting goods, high priced diesel can help drive up the prices of products and services.
Drivers in Hawaii, the state with the most expensive diesel, paid an average of $5.337 a gallon for diesel. Diesel was cheapest in Missouri, where prices fell to an average of $4.125. 
