Filling Up A Gasser/Pump Limits

What we do is ask if they can override the limit inside. Some can and do. Others say they can't, so we prepay for an amount with our debit card. We pump and if we end up with less gas and charge than we estimated, since we used a debit card, the excess payment that was made goes right back on the card immediately. When the bank processes the debit, only the amount of your actual pumped amount will go thru your account. If we could still add more, we don't usually worry about it.