I live in florida with virtually no hills, my commute is 16 miles each way mix "highway"/city, mostly rush-hour, and plenty of stop lights and stop-and-go. I'm pretty delicate with the gas pedal, because let's face it the 4runner isn't going to go anywhere fast anyway, and I'm conscious of traffic ahead to gauge my driving habits (I get passed by the impatient people, but I'm ok with that).

2002 2wd 5VZ auto, stock everything and my first full tank I got 309 miles on a 16.3 gallon fill-up (works out to just shy of 19MPG on 87 octane). Just about what I was expecting, not amazing and not terrible. Although I'm used to having to fill up with 93 octane in my daily driver, so I'm still saving on gas and happy about that.

just adding my experience to the thread.