Quite respectable I think. I just picked up an '03 Ranger 4x4 4.0l, its been getting 17mpg (well 16.9-17.2) dead reliable no matter what we do, city, highway, mix, 4wd, 2wd, loaded or empty doesn't seem to matter... Speedo is within 5% at all speeds (sometimes closer) verified with GPS.
The '96 Dodge Dakota the Ranger replaced got more like 12mpg city but closer to 20mpg highway and had a helluva lot more space in the cab, wasn't as good offroad though. EPA estimate for the Ranger is 17 highway...