I would suggest filling up on Disney property. The last time we were running late, forgot to fill up before leaving the resort area and couldn't find a gas station on the way to the airport. It seems like you cannot see any gas stations from the road you are on. Who knows what exit to take? Very confusing, especially if you are running late. We plan to fill up on WDW property and will not worry about the $5 extra it will cost for higher-priced gas, as compared to an extra $35 for having the rental company top off my tank!