Hi Robie,
     Your mileage seems about = right.  My 86' Syncro gets around 17 to 19 MPG at 70MPH.  If I really try = and drive easily, I can get 20 MPG.  Most of my driving is at highway = speeds.  I drive 50 miles round trip to work.  I usually get about 295 miles = to the tank full, 16 gal. 
 
     Sorry no = armrests.:0
 
Colin Moran
86' Synro GL "The Bronze Brick"