Gas falls for 19th straight day
The average price of regular gas falls to $3.871 a gallon, according to national survey.
NEW YORK (CNNMoney.com) -- Retail gas prices fell for the 19th straight day, extending their multi-week slide, a daily survey of gas station credit card swipes showed Tuesday.
Gasoline: Regular unleaded gas fell a penny to a nationwide average price of $3.871 a gallon, according to a survey from motorist advocacy group AAA.
The average price for regular has fallen more than 24 cents since hitting a record high of $4.114 at the pump on July 16, according to AAA. The slides comes amid a steep drop in crude oil prices.
Still, the price of a gallon of regular gas remains more than $1 higher than it was a year ago.
Ethanol: Ethanol prices jumped higher. The price of E85, an 85% ethanol blend which burns cleaner than straight gasoline and is made primarily from corn, rose 1.7 cents to $3.142 a gallon on average, AAA reported.
High gas prices have caused many drivers, particularly those in regions with strong agricultural industries such as the Midwest, to switch to ethanol as their fuel of choice.
While ethanol is derived from renewable sources, it is less efficient than gasoline. As a result, a car running on E85 would pay the equivalent of $4.135 per gallon to get the same mileage as gas, the AAA survey estimated.
Diesel: The average price of diesel fuel, which is used to power most trucks and commercial vehicles, fell to $4.644 a gallon from $4.654 the previous day, according to AAA.
Diesel prices have climbed nearly 57% in the last year, driving up costs for businesses and inflating the prices of the goods and services those businesses provide.
State prices: The AAA survey, which averages data from credit card swipes at 85,000 fuel stations around the country, showed that gas remains above $4 a gallon in 11 states and the District of Columbia.
Gas in Alaska, the state with the highest prices, fell to an average of $4.646 a gallon from $4.647 the previous day. Hawaii, the state with the second highest prices, saw average prices rise slightly to $4.466. California, the state in third place, saw prices slip to $4.197 on average.
Drivers in Oklahoma, the state with the cheapest gas, saw prices hold steady at $3.611 a gallon compared to the day before. In Missouri, the next cheapest state for gas, drivers paid $3.633 on average, followed by Minnesota at $3.646 a gallon.
Drivers in Hawaii, the state with the most expensive diesel, saw diesel prices rise to $5.382 a gallon. Diesel, on average, was cheapest in Oklahoma at $4.422, according to the AAA survey. 
