I do not have a westy (I have a Wolfsburg with the table, removable
rear-facing seats and fold down bed), but for the the time I have owned it
(since early 1993, second owner) I have averaged about 25 mpg in summer and
about 20 mpg in winter.  Difference has been due to oxygenated fuels we use
in the Denver area in winter.  At best, my bus gets about 29 mpg, at worst
18 mpg.
--
Mark A. Williamson
Denver, CO
88 Wolfsburg Weekender (135K)