Well I drove to from NY to Central Florida in my 85 and I would fill up   
about every 250 miles.  Once I did manage to reach 290 before reaching a   
gas station to refill.  City driving, well I ran aout of gas one time at   
exactly 250miles.  My guess is that I can probably reach 300 miles at   
highway speeds.  That works out to be about 15.5 city/18.75 highway.

Nate El Great
154k Mi 85 Vanagon GL