The average U.S. price of regular-grade gasoline held steady over the past two weeks, at $3.49 per gallon.
Industry analyst Trilby Lundberg of the Lundberg Survey said Sunday that spiking ethanol costs prevented a drop in gas prices.
The average price at the pump is $1.31 higher than it was one year ago.
Nationwide, the highest average price for regular-grade gas is in the San Francisco Bay Area, at $4.82 per gallon. The lowest average is in Tulsa, Oklahoma, at $2.95 per gallon.
According to the survey, the average price of diesel jumped 2 cents to $3.69 a gallon.