Pump prices fall; oil prices up slightly

Gas prices are finally heading lower, but motorists shouldn't expect the numbers at the pump to drop quickly this autumn.

The national average for retail gasoline fell about a penny Friday to $3.833 per gallon, according to AAA, Wright Express and the Oil Price Information Service. That's down 4 cents from a week ago, the biggest weekly decline since early summer. The average price is still 50 cents higher than on July 1.

Gasoline prices typically drop in the fall as refiners begin selling winter blends of fuel, which are cheaper than those used in the summer to help curb pollution. This year, however, supplies are tight because of refinery outages in some regions, including the Gulf Coast due to Hurricane Isaac. And the gasoline futures market, which dictates the price at the gas station, has been volatile. That all adds up to gradual relief at the pump.

The lowest average prices ranged from $3.592 to $3.70 and couldn be found in New Mexico, Texas, the lower Midwest and parts of the South.