new to diesel

I send my DW in to pay and get the pumps turned on. I pretty much know how much I am going to take, since my Aladdin is fairly accurate on how much fuel we have used. I have her prepay the appropriate amount and the cashier will credit any amounts we don't use. If that doesn't work, DW stays inside and completes the sale when I call her, then I pull forward, collect her and away we go. In Canada, Alaska and some Western states, we use the "cardlock" fuel depots when available. Their fuel is usually lots less, and the lots usually almost empty.