Over the past month or so, I've started driving around 55 to 60 mph on the highway versus up around the speed limit of 65 mph. This has resulted in improved gas mileage of around 1.5 to 2 miles per gallon. I get around 25.5 to 26 cumulative mpg following this new pattern. I'd heard of gas mileage savings by driving at a slower speed but had not previously tried it.
This will end up extending a tank of gas by roughly 1 gallon per tank. I fill up an estimated 26 times per year so at 26 x $4 that equals a savings of $104 per year just by driving 5 to 10 mph slower. Many people fill up more frequently than this so they could potentially save even more. Try it, it works.
To find out the cheapest gas in your area try out one of these links MSN Auto Gas Prices or Gasbuddy.com.