This was actually a hire car I got from Avis just for a change.
I thought it might be useful for first time drivers in Florida to explain how the petrol / gas stations work. In the UK you fill up before paying, it works the opposite way in the Florida. Obviously there's a bit if guess work with regards to how much the vehicle will take, so maybe just add $35 as your first tank to see how much of the tank that fills. This is the same process throughout America.
If you have a US credit / debit card you can use the keypad on the pump to pay.
It's more likely that you are using a UK credit / debit card and therefore you will not be able to use this set up, as it will ask you for a zip code that's connected to the card. Instead you will need to go into the gas station and request that a certain value is credited to the pump where you have parked, you then pay for this amount. Should you not be able to fit the full amount requested into your car you will only be charged for the amount taken, if this is the case I recommend getting a receipt for the actual amount paid. If you wish to use cash, you still need to pay ahead of filling up.
If you are hiring a car from either Orlando International or Sanford airport you will pick it up full and they will ask you if you would like to prepay for the petrol / gas up front so that you can bring the car back empty or bring it back full. I prefer to bring the car back full as you will normally pay more per gallon at the car hire rental desk than on the local petrol pumps but it depends how well you know the area and if you can be bothered to fill up on your way back to the airport when most people are a little stressed that they have got everything.
I normally fill up on HWY192 on my way back to the airport which is 15 miles away from Orlando International and then just drive it back as there aren't any gas stations at the airport that you can use. As long as the fuel gauge is still at the top you won't be charged for any extra fuel.
One tip I would recommend is that when you get back to the car rental return you wait for the attendant to come and check the car over, record the mileage and then scan the bar code in the window, they then print out a receipt which shows any extra charges and what you paid for your car hire. This is a great thing to have incase there is a problem at a later date with your car hire.
We hope the above information helps you when driving in Orlando and if you have any tips you think other visitors would like to know please leave a comment below.