(Portland, OR) -- Gas prices are falling across the country. Triple-A reports the national average declined 17-cents to three-dollars-98-cents per-gallon, while Oregon's average fell 15-cents to four-dollars-62-cents. The lower prices are due to cheaper winter blends of fuel, lower demand and increasing refinery output as maintenance projects are completed. Diesel in Oregon is down eleven-cents per gallon to six-dollars-60-cents.