Avis offers to fill your tank with gas at approximately the going rate $3.20 (in sf) when you return their rentals. Sounds like a convenience, but beware! The contract states that you will be charged for a FULL tank of gas regardless of how much is in the tank when you return it! in my case with a chevy impala the cost was over $60, even though i returned it with more than 1/2 tank of gas in the car. Heavy taxes are also applied to the gas fee. Forego this one and fill up at a nearby gas station before returning the car.