I just managed a best of 21 MPG's with my 2001 Dodge Ram quad cab shortbox SLT 2wd with a 5.9L Magnum. grnated my truck has a bit of work into it to make it more efficient, but 2wd 5.2L's should easily get 17-20 MPG's in nearly stock form (highway, of course)
1969 Dodge Super Bee A12 (440 Six Pack, 4-speed, Dana 60 4.10)