re: Tires and rims...please help me with sizing basics (A4)

[Jason Palmer <palmerj@earthlink.net>]

todd.stone@mailexcite.com said:

>First, my stock tires are 205/55 R16 W.  Could/should I go to a 215 tire for
>enhanced performance without changing anything but the rims?  (the manual
>does not address this) 

The plus zero upgrade has been 225/50/16. I don't have the numbers, but
the diameter difference is pretty small.

>Second, could/should I go to a 17" rim, again, for performance gains?  The
>manual warns against changing overall configuration as it will affect the
>Quattro differential (not to mention speedometer, trip computer, et al).
>Is there an optimal tire/wheel size combination for "modified" A4's that
>takes care of these problems.  I'm NOT looking for competition specs (I
>still have to drive to work), just wondering if there are "standard"
>modified specs.

I did... 17" wheels, 225/45/17 (as recommended by Tirerack and many
others)... really makes an improvement.
As long as you use the same wheel size and tire on each corner, there is
no problem. The manual addresses using an odd tire in a set. The speedo
could be off, but its not enough to fret over.

2 things to consider- the shorter sidewall and additional wheel will
transfer more road noise into the interior. A good tire will minimize
that. I got a great set of toyo proxes T1s and it rides as well as the
16" wheels w/o the rollover and tiresqueel.
Second... the 45 series tire leave little margin for potholes and other
wheel bending hazards. Look for a strong wheel. Those thin spoked wheels
with sharp radius are trouble. I bent my Porsche replica 5 spoke, it
took hitting a curb pretty hard to do it.

With the wider tire and wheel, the A4 looks more aggressive... 

I have some shots of my car at
http://home.earthlink.net/~palmerj/ and look under the "What I've done
to my little car" section in the Mods.

Jason Palmer
97 A4 1.8Tq mtm w/ Toyo Proxes T1s on 17" alloys
88 GTi Pirelli and Michelins (ask PO!!) on factory teardrops
80 MGB Bridgestone R-compound slicks on Steel RoStyles!