IRVING — Retail gasoline prices continued to plummet across the state this week, according to a weekly survey.

Regular grade gasoline averaged $2.68 per gallon at self-serve pumps across the state, down 5 cents from last week, according to the weekly AAA Texas gasoline price survey released Friday. Nationally, regular self-serve prices fell by an average of 5 cents a gallon to $2.76.

The cheapest gas in Texas was in Corpus Christi, where regular self-serve prices fell by an average of a nickel a gallon to $2.54. The state's most expensive gas remained in Amarillo, where it fell a nickel a gallon to $2.83.

“During these summer months, gas prices have dropped in nine of the past 11 weeks,” said auto club spokesman Paul Flaningan. “Despite a two-week spike in July, state prices are at their lowest levels of the summer so far, although they are more than 60 cents higher than they were in February of this year.”

Following are average per-gallon prices of regular, self-serve gasoline in Texas metro areas and the change from last week, according to today’s Triple-A Texas Weekend Gas Watch:

Amarillo - $2.826, down 4.9 cents

Austin-San Marcos - $2.712, down 4.8 cents

Beaumont - $2.650, down 5.5 cents

Corpus Christi - $2.536, down 4.5 cents

Dallas - $2.656, down 5.7 cents

El Paso - $2.746, down 6.0 cents

Fort Worth - $2.647, down 3.7 cents

Galveston-Texas City - $2.658, down 3.9 cents

Houston - $2.629, down 5.0 cents

San Antonio - $2.696, down 4.3 cents

Texarkana (Texas only) - $2.675, down 5.0 cents