Gas Prices

I have come to the conclusion that it is cheaper to buy gas on Tuesdays and Wednesdays than any other day of the week.  At least it seems to be true in Oregon.  I have been tracking gas prices for 2 months now, and my investigation shows that on Thursdays it seems to be the day when the gas prices go up, and my assumption is to gouge consumers for the weekend.  So, if you must fill your tank each and every week like I do....  Tuesday and Wednesdays seem to be the best (and cheapest) days of the week to buy gas.