Well my wife gets better mileage than I do, but then I do a bunch of short hops in mine. She normally goes about 330 to 350 miles per tank, while I go about 320 to 330 miles per tank. I also do a lot of city driving when I'm out and about.
On our last road trip to Texas in her car, we did a lot of highway running, and got gas about every 350 miles or so (not letting the tank drop below 1/4 tank), as gas stations can get few and far in between depending on where you're at, or whether it was time to get something to eat. We also spent 7 days running around once we got there, taking care of other business. When we got back, I ran the mileage versus the fuel burned, and we averaged 26.79 mpg for the entire trip. Keep in mind that I had the cruise on-set to 80mph, and we had the AC on the entire time as well. I felt that wasn't too bad all things considered.
I/we never let the fuel level drop below 1/4 tank, due to the fact that driving with a low fuel level like that can burn up the electric fuel pump (it doesn't cool well with less fuel). This is something I learned years ago, and still practice today. And while I can replace the pump for around a 100 bucks (dealer gets over 400 to change it), if I can keep the OE pump going, I prefer to do so.