I use http://gasbuddy.com/ and have not had a problem. Most stations have at least one a cc machine one of their fuel islands.
What gets me mixed up is some stations have several differant grades of diesel fuel (winter blend, number 1, number 2 etc)
If you look up F/J on map and use gasbuddy you can see most f/j are for lack of better term "anchor tenant" for a fueling area. Most of their stations are big with easy access on/off the freeway etc..but across the street or within 2 miles there is someone usually for less. However, I don't buy fuel from real small stations because I want the fuel to be "fresh". I also try to fill up when I gauge gets on 1/2, (time for a break anyway). Theory being if I ever do get bad fuel it will be mixed with good fuel (already in tank) and only MPG will suffer and not stranded somewhere. (I always have filters on hand, you never know)
As an example right now Fred Myers in Monroe WA(where I normally buy) is selling fuel for $4.07, then with 5% back from Penfed = $3.87 gal. And also take off their reward program which sometimes = .10 a gal off, but their rewards depends on how much points we have at the time.
So $3.87 gallon net after Penfed. And their neighbor right across their parking lot is a 76 station and right now they are selling for $4.19 so for driving 1/2 block I'm getting fuel for 32 cents less per gallon while looking at the 76 sign and pumping in cheaper fuel.