Questions about tire stuff....

[rdh@sli.com (Robert D. Houk)]

   Got a question regarding tire sizes,  I have an 89 100, with 205/60/15
   Michelin mxv2 tires that are quickly approaching the surface texture of
   a boloney skin.....:-)  Some of you may remember me asking questions
   last year about which tire to replace these with, well the time has come.
   I've decided to go with either P500 or COMP T/A HR4's but my one nagging
   question is I'd like to go a little wider, to maybe 225.... But what's
   this gonna do to my speedo ?  How much faster do you think I'll really be
   going when the speedo say's 60 mph ?

Assuming you mean 225/50/15, your speedo will read about 6-7% high (as I
recall, 70mph real was 74 indicated on my '83 Ur Quattro). If you can find
a 225/55/15, you should be "Real Close Now". Before you try to widen your
tires, make Very Damn Sure you have sufficient wheel-well clearance at
full lock and max suspension deflection to handle the extra width! Else
you will be rubbing tire against body work (quickly exposing bare metal to
the rusting elements of weather) or other unforgiving objects. Also make
sure your wheels are wide enough to properly support the sidewalls of the
wider tires. Ideally, you should go to 225/50/16's (which of course means
new wheel$ as well!) - this "plus one" configuration maintains almost ex-
act speedometer accuracy (the variation in actual tire diameters from the
different manufacturers will be the determining factor - my experience is
that Yokohama tires tend to be a tad larger diameter for otherwise same
specifications).

I ran 225/50 Yokohama A008's and while the handling *almost* matched my
old Europa as far as steady-state carving through a, e.g., freeway onramp
was concerned (i.e., max G-force turning/braking), the overall handling
really sucked as far as day-to-day cruising to work was concerned. The
car was very "nervous" and a constant battle just to try to negotiate a
straight line (every road surface imperfection would deflect the car in
a new and interesting direction). Now this is OK (and in fact *highly* de-
sireable) in a 1500lb zero-Ackerman-2-turns-lock-to-lock-steering-geometry
Lotus Europa, but not so hot in a 3000lb German Beast trying to cruise the
long-and-straight interstates (as found in, for example, Kalifornia and
Kansas). Handling was, um, "harsh". So be wary of the tradeoffs.

For all-round goodness, I highly recommend the Yokohama AVS A+4 series.
For any specific application you can find a superior tire, but for running
the same tire winter and summer, wet and dry (and *SNOW* Yay!), you can't
do much better in a proven tire. (There is supposedly a new tire out from
somebody with a fantastic new tread compound to drastically improve cold
and wet handling, but I haven't heard of anyone's Real World experience
with them yet. And I don't know how their hot and dry handling is. I think
they are called "Blizzards" or some such vaguely-similar name???) Are you
willing to run different "winter" and "summer" tires?

					-RDH