My story is not so much cheapskate as illogical. I have relatives who will drive miles to get the cheapest gas, but the gas is maybe only one or two cents cheaper than a much closer gas station. I never did the calculations, but I wouldn't be surprised if they spent more money traveling to the farther gas station than to get the more expensive gas.
I've actually done the calculations. My car, and my last one, both had 18.5 gallon tanks. I generally try and fill up weekly, to stay on budget, so figure 8-9 gallons. if you save .3 per gallon by driving out of your way, that's a whopping total of .27 PER WEEK, and just over $14 a YEAR. Yeah, my time is too valuable to be traipsing all over eternity and back to save that little.
I will say for me sometimes, its a mental thing. I won't go too far out of my way, but will wait, if gas is .10 more a gallon. still not a huge savings, but its the idea of it, for me.
Thankfully last summer they added gas at my local Costco, which is right by where I go weekly to grocery and other shop, so I just swing by, and fill up. And if I'm not up that way, and need gas, I just go wherever its convenient.