100,000 Miles on the Ford Explorer

I've just passed 100,000 miles on my 1999 Ford Explorer, and some time in early July marked six years that I've had it. I have fluids changed regularly, and it's still running well. Unfortunately, a few problems have developed: the driver seat back doesn't stay upright, and the cruise control doesn't work anymore for some reason.

Of course, the big problem is gas! City driving, it gets about 13 miles per gallon; on the highway it gets about 18.