I normally use Pilot or Loves truck stops. You go inside to turn the pump on, they ask you how much you want to pump (ie, $70, $45, etc), then they run your card and you sign for that amt. If you don't need an official receipt, you can just scratch out the amount you asked for and write in the actual amt. That way, you don't have to go back into the truck stop. IE, if you asked for $70 and only use $62.69, just write that amt on your receipt for your records. That's all they will charge you.
The high flow nozzles aren't a problem. I usually set it on the lowest volume notch. Sometimes you have to hand control it, but it doesn't take long. Don't walk away from the pump during filling, sometimes(very unusual) the auto shutoff doesn't work. You will be charged for whatever pumps out, maybe charged with cleanup too.
