Re: Upsizing wheels/tires on 93 90CS

[Chris Newbold <Chris_Newbold@transarc.com>]

Randy Bindrup wrote:

> The car currently has the 15" flat face alloys, 4 x 108 bolt pattern,
> 37mm offset with 195/65/15 tires.  I have seen another 93-95 90S that
> had 16" wheels with 225/50/16 tires.  Is this a difficult fit?  Doing

Trying to wider than 205 puts you off all the "official" fitment guides
and you'll be on your own. Niether Tire Rack nor Discount Tire have any
"approved" fitments > 205.

> the calculations for size, it should work if the offset is correct.  Is

Yeah, but you may need a Sawzall to get them under the fenders...

> anyone out there running this setup?  What wheels are available
> (probably not many because of the bolt pattern)?  Another calculated

That's right, the bolt pattern does restrict the choices. All of TSW's
wheels are available that way, a number of Borbets (Types, C, E and T
if I remember). Then there are a bunch of Italian-made ones, can't
remember the names, but they're all boat anchors...

> size is 225/45/17 that should fit very close.  I have 45 series tires on

I've been researching 17" setups a bit for my track tire/wheel combo.
In a nutshell: may not fit without modifications, will cost ~ $500 more
than a 16" combo, isn't really _that_ much wider.

> another car and the ride is not too impressive, but they look sooo
> nice.  Let me know what options are available.

Your best bet is a 205/55 tire on a 16"x7.5 wheel; you'll want something
like a 35mm offset. This setup is fairly easy to come by, and the tire
size is popular, so they aren't outragously expensive. The 7.5 wheel
stretches the 205 out nicely, so you get a good square profile, lots of
contact and not much sidewall flex.

You could do 17" wheels, but I think you'll find that no one makes a
205/50 17 tire... At least not cheap.

The other thing to watch out for is that many of the fitment guides in
use have the wrong information for these cars. They'll list the OEM fitment
as a 14" wheel with a 45mm offset (which was the setup of the previous
generation). Make them cross-check with a '95, or with a quattro, all of
which seem to have the correct information.

-Chris
1993 90CS 5spd 73k miles