sounds about right.
Your speedometer should be running faster than actual road speed, and actual odometer readings are slightly off.
Figure out how much of a % the difference between stock tire height 205/75/14 or 195/75/14 and apply that to your mileage.

If I do my math, I get 19mpg according to the speedometer/odometer, but I divide in 83.333% and I get about 23mpg with this last fill up, for me.

that's pretty damn good, Bern! considering that 4.0L is barely working to move that Toy

 

What size is the gas tank?

 

So I average around 26 in town and 31 highway. Mostly stock. Only cut a couple of holes in my stock air box and run a K&N filter. Then I run a Magneflow cat and a Flowmaster Super 40 series muffler. I think I'm running 195/70/14s and a 4spd trans. And it has 294,440 miles, and still running like a freakin champ!!