They have fleet fueling stations where we’re at. Car dealerships use them as well as cops and anyone else that needs it.

My father used to repair gas pumps for a living. I went out with him on a few jobs. You’d be amazed how many large facilities that have their own fleet of cars end up setting up their own gas station. Universities, large hospitals, movie sets, and of course emergency vehicles.

Where I live (Germany) they usually have cards with which they can pay at most big gas stations. Kind of like a pin protected voucher card. They usually have a maximum limit though.

So when we operate a mobile gas station in catastrophic events like big wildfires etc. We usually have to get a limitless card, because otherwise we need a new card 3-4 times a day because we refill our 450 liter tank so often.

Most fire stations and probably police stations too have an emergency depot though. As does the city. Sometimes the city depot is shared with the depot of the public transport company though.

In my town they fill up at co-op Cardlock, same as the truckers but gasoline instead of diesel

Back when I worked IT for the city we actually got a tour of the main police station. There was a gas pump on sight where officers could make sure their car was full before and after patrols