The PenFed card must be swiped at the pump and is good at 99% of the fuel stations. One that is not is Arco but I pay much less down the street with the 5% cash back.
We also use the Kroger/Frys/Fred Myers/etc rewards card to get a 10 cents/$100 grocery purchase fuel discount. 35 gal limit.
Safeway is similar with a 25 gal limit and alcohol is excluded. We'll see what develops with the pending purchase of Safeway by Albertsons.
The 25/35 gal limit also means that you won't get the full advantage of the reward if you put say 15 gal in your car but that is no issue with Kroger and our diesel RV.