Grocery stores chains like Giant Eagle and Kroger like to give discounts on fuel when you buy gift cards. If they have gift cards for places I’m already going to anyway, I use them as much as possible. I even buy GameStop gift cards that I take to GameStop to buy gift cards for other places, earning points twice. Gift cards have their own problems but save money when you can by buying them for yourself.
Source: the receipt from my Giant Eagle visit just now, scanned with my printer