As others have said, I only take the fuel option if I am going to use a lot of fuel and might have issues topping it up.

For example, two weeks ago we drove from IAD to LGA. I wasn't going to worry about finding a gas station near LGA at 4:00am when we dropped the car off.

This week I've got a car in London. I also will be around Gatwick early, and don't know where the gas station is. And the car's under a 1/4 tank now so it'll be pretty doggone close when we turn it in tomorrow morning (and we've put fuel in it during the week).

Steve