At least it is presently a little under US$6 per gallon. It was over that for a while. I have a Honda Civic. I fill at about the one half mark, although we all know gauges are not so accurate, and it costs me usually about €41, which is presently about $52 in converted $.
Usually from 8 to 1 there are attendants unless it is their "turno" in which case it is open but you have to shove euro into the machine. Big highway stations (distrbutori) have longer attended hours and don't close during the pausa. This can be important if you have tire issues, etc. I cannot remember seeing any stations where you could use any but their own CC when the station didn't have attendents, but almost all of them will take normal CC during attended hours. (All, in my experience.)
The cards of the gas stations are not real credit cards, you use them if you want to accumulate points, for nothing else. I hardly see gas stations that not use credit cards. Maybe the TINY single pump in the middle of nowhere, but you keep driving and you'll find something else. Autostrada stations are open 24/7.
Alessandra, I think USians are looking for gas stations at which you can put a charge card into the machine when the station is closed (or open) to pay for gas. I never see that here...do you? In the US I would pull in, put my CC into the pay machine, pump gas and then drive away. Here I can charge it only when they are attended. The Agip near me does have an Agip CC that can be used, however. I have the points card but not the CC.
I saw them here. I am positive about the use of machines that use cc. At least in this part of tuscany. I cannot be sure about it in other parts of the country though