On my last trip...Pullman, WA to Butte Montana with 3 friends

25 MPG on the way there ( "Backroads" route)
23 MPG on the way back (Freeway route)

I usually get about 19-21 though
With a bike or two on the rack...about 15 MPG

It's a 1985 Vanagon GL
133,450 miles

- Aaron