(Portland, OR) -- The price of gas in Oregon is up while the national average remained steady over the last week. The Triple-A says Oregon's average increased eight cents to 4-dollars-29-cents a gallon. The national average is 3-dollars-54-cents. Oregon's increase is the eight-largest in the country. Refinery maintenance and increased demand have reduced supplies which causes prices to rise. More expensive summer blends of fuel are reaching pumps and the cost of crude oil is over 80 dollars a barrel which also puts upward pressure on prices.