Hi-
I finally did it.  15" alloys and tires for our = '88.  I really wanted to go with a larger diameter tire, but not a = wider one.  The reason was that I wanted to bump the gear ratio a little = for less rpm's at cruise. 
The size that I wanted was 205/70-15 on a 7" wide = wheel.  I could not find this size in light truck tires, seems most 15" tires = are the 245/75's etc. monster meats aimed at Range Rovers and Toyota Land Cruisers.  I started the process by asking Discount Tire = Direct http://www.discounttiredirect.com/ about the Mercedes Replica wheels that they sell.  Intitially = they came back saying that they had done this on a Vanagon before, and in fact = showed these wheels on their website as a Vanagon application.  When I = pushed them for details, I heard from a manager that they had figured out that lugs = nuts and studs would not work correctly.  Within a couple of hours the = Vanagon app.disappeared from their website.  Heard again from them.  = They could get a TSW (better than oem quality, made in South Africa!!)  = 5 hole Mercedes replica wheel that would work.  15x7,  5x113 bolt = circle, 23 mm ET, correct strength rating to carry Vanagon loads.  I said = OK.  Now for tires, this got interesting.  I learned that on passenger = car tires the weight capacity is found in the tire sizing info ie: 205/70-15 = 95V.  The key is the "95".  Most car tires are either 92 or 93 (I think a = key for these numbers is in the archives). D.T. said that the only tire that = they could recommend to me in that size was a Michelin "Energy" MXV4.  = The "V" rating was not suggested for speed capability (obviously), but because a = V speed rating also means greater carcass strength. These tires are = intended for the big Mercedes and BMW's that have to be as heavy as my Vanagon. = Made sense to me. Not particularly cheap at $105 ea.
 
The mounted wheels and tires arrived, and I began to = install.  Had to take care of a couple of things.  The small = bolts holding the rear brake drums had to go, and the speedo cable on the l/f = hub had to be filed to shorten it a bit.  My oem nuts and studs (had = original alloys before), fit the seats in the wheels perfectly.  They are a = bit short though, and I will replace. What a transformation.  Ride = quality is amazing, handling amazing, wind stability vastly improved.  The = apparent gear ratio increase is exactly what I was looking for.  Cruising = with fast traffic now keeps RPM's under 4k.  Went through a measured mile, = and found that my formerly optimistic speedo is now spot on.  The wheels are = very well made, similar in basic design to the originals, with gorgeous = silver epoxy paint. 
 
A very satisfied customer.
 
Gary