(Portland, OR) -- Gas prices are trending down because of cheaper winter fuel and refinery maintenance is ending. Oregon's average is down eight cents to $4.77 a gallon. The national average is the highest ever for a Congressional election day at four-dollars-and-15-cents for gas and six-29 for diesel. Oregon's average is the second highest for a Congressional election. The record was set November 8th, 2022 at four-83 a gallon.