(Portland, OR) -- The average price of a gallon of gas in Oregon increased 33 cents over the last week to four-87 a gallon. Triple-A reports the national average is up 19 cents to three-98. Both the national and Oregon averages for regular gas have jumped about a dollar per gallon since the Iran war began. This is also the time of year when more expensive summer blends of fuel cause prices to rise. Diesel in Oregon averages five-93, which is an increase of 45 cents over the week.