Average gasoline prices in Texas have fallen 6.4 cents per gallon over the last week, to $3.66 a gallon, according to GasBuddy's survey of 13,114 stations in the state. GasBuddy said Texas prices are 23.3 cents per gallon lower than a month ago and $1.09 per gallon higher than a year ago. The cheapest Texas station was priced at $2.99 a gallon yesterday, and the most expensive was $5.65 a gallon, a difference of $2.66 a gallon, according to GasBuddy price reports. The national average price of diesel rose 4.0 cents from a week ago to $6.340 per gallon.