Instead of playing the game of maximizing the cost, reduce the usage. That will have a much larger effect than trying to gain a few cents as prices increase over time.
My dad was born in 1943 and would tell us a story about the corner gas station where the price had always been a fixed 29 cents a gallon since he could remember. At some point, as a kid, he noticed when it went up to 30 cents and realized it would never go back down. What caused the increase, who knows, but it's funny to plug in 28-30 cents into an inflation calculator and find it's the same as $4.00 in today's dollars.
You know what was different, though? Wages. While we do need to use less oil for lots of reasons, including cost, resources, and environment, that isn't why gas prices are a problem.