Jeff,

Your question is made somewhat unclear by the (14") part at the end.   I
would assume that you simply mean that you Syncro has 14" wheels or came
with them and that you are going to change to/use  15" wheels to mount
these tires.

In short, the answer is yes, but this size tire is on the edge of tires
that might have clearance problems when turning.  It will depend on
which 15" tires you choose and their offset, and whether you use spacers.

There are dozens of threads on tires for the Vanagon in the archives of
this list and the syncro@yahoogroups list.  You might also find some
good info at the syncro.org website.  Go to these archives and use this
specific tire size as the search term to hit the specific posts that
discuss the potential issues with a tire that wide in detail.

http://gerry.vanagon.com/archives/vanagon.html

It can work with the right wheels.

Sam

--
Sam Walters

Baltimore, MD