In my morning commute, I keep an eye on gas prices if I need gas on the way home. While the cheapest gas in town is about two and a half miles further past my work, it doesn't make sense to make a special trip to save three or four cents a gallon. According to fuelly.com, my van's year round average is 19.3 mpg or 17.3 cents/mile at $3.339/gal (last fill up).
Driving five extra miles, two and a half there and back, to make a special trip for the cheapest gas would cost me 86.5 cents. Saving 86.5 cents means the cheaper gas would have to be over four cents cheaper for a 20 gallon tank. It would have to be eight cents cheaper on a 10 gallon fill up. Factor in the time saved, and it's not worth it. I only fill up at the "cheap" gas station if I'm already out and driving right past it.
by jgibbsjr on March 27 2011
this tip works for 98% of voting Fuelly members.