An interesting aspect of the Speed Pass and most credit/debit cards while paying at the pump is that when you "get approved" after using whatever credit/debit device, a charge is placed on that account immediately for the MAXIMUM amount that particular station will approve. Once you have completed your transaction, another charge is placed on the card for the "actual" amount. The original charge can stay on the card for up to fourteen days. I found this out a few years back when we took the pit bike to California and back. It takes nearly 90 gallons to fill the beast, so when I used my Speed Pass device at the truck stops, they chunked in a charge for 250 to 350 bucks (the average cross country truck credit limit without extended approval). I would then proceed to put in 80 some gallons and be on my way. Once I got to my parents house in California, I took everyone out to dinner, but my card was declined as over limit. Turns out I had over $1500.00 of "Approval Charges" still pending and it took nearly an hour of screaming at the CSR before they would approve the dinner charges (I paid cash in the meantime, but was on the warpath when we got back to my folks house after dinner).
It may be your money, but they love to use it . . .