When we pre-pay, we normally wait until the tank is about empty and give them $50. It's usually just enough to completely fill the tank. If it's too much, the pump will stop when it is full, then you go back inside and the clerk will see how much money is left on your pump, give you what you are owed, and then reset the pump. To avoid such "inconveniences, many pay with a credit or debit card outside at the pump. But even that has its cons, some places put a large hold on your account until the money for sure goes through (which could take several days, depending on a lot of factors). There is one truck stop I know of about an hour from here that puts a $250 hold on your account until the purchase finalizes.
Blimey,KR-that seems like an awful lot of distrust,hon. The only time I've seen anything remotely like that is when I'm trucking through Europe,where sometimes we have to leave the fuelcard on the counter before filling. But even then,it's just a case of leaving it on the counter,filling the tanks,then going in and saying which pump number you used for them to transact it. But it seems fuel theft is major over there? Sometimes,I wonder just how low humans can sink before we finally start to ascend again... .
I haven't seen a gas station where you don't have to pre pay in years and years. Ever since gas prices spiked so much a few years ago. I've made a couple of observations myself regarding the business practice of certain minorities. The delicious Columbian restaurant I frequent always tells me, "We are in America but we are Colombia and your money is no good to us until you enjoy your food," if I try to pay after I get my food but before I eat. The middle eastern restaurant I love that is ran by both an Israeli and a Palestinian let me take my food last week for $10 when the total was $10.43. I only had a $10 bill and they decided my business was more important than 43 cents. Once before that, I didn't realize they didn't take debit cards and they let me take my food for free and told me to just bring cash back to them later that day. So it really goes both ways.