Jerry,
You mean tires, not wheels, right? From the only copy of section 13.4 I can
find on the web (on your server):
13.4 Wheels
Any type wheel may be used provided it complies with the following: it is
the same width and diameter as standard, and as installed (including wheel
spacers if
applicable) it does not have an offset more than +/- 0.25 inch from a
standard wheel for the car. The resultant change in track dimensions is
allowed. Vehicles
originally equipped only with 12 inch diameter wheels, may use 13 inch
diameter wheels of the same width as standard and offset within +/- 0.25
inch of
standard.
Where the definition of standard is:
12.4 Standard Part
An item of standard or optional equipment that could have been ordered with
the car, installed on the factory production line, and delivered through a
dealer in
the United States. Dealer-installed options or deletions, except as required
by factory directives, no matter how common or what their origin, are not
included in
this definition. This definition does not allow the updating or backdating
of parts.
End quote.
So it seems clear to me that to run in stock you must use wheels of the same
width and diameter as what was available on your car, either standard or as
a factory option. Offset can vary, but only by +/- 0.25 inch, which isn't
much. Also, if your car was available with a different size wheel as part
of a "sport package" that included other upgrades, all those upgrades and
not just some of them must be done. Since the M3 came with 17x7.5F/17x8.5R,
that's what you have to use. You can't even switch them front to back, I'm
pretty sure.
What is *not* restricted is tire size, provided the tires fit the rims and
don't stick out past the fenders when viewed from above.
Peter
-----Original Message-----
From: Jerry Mouton [mailto:jerry@moutons.org]
Sent: Thursday, April 26, 2001 2:13 PM
To: Mike Eynon; ba-autox@autox.team.net
Subject: Re: M3 tire question
Mike,
I can't help too much with your M3 questions, but
I thought I'd mention that I believe that based on the
stock class rules, it's not necessary to go with the same
stagger front to rear that the car came with. The rules
allow ANY wheel of a size near what was shipped with the car,
and it's not in the class of "a complete option set", as the
rule allows wheels that are not of the exact same size, even,
that was offered on the car. I run same size front and rear,
as do most 911 drivers I know. Some Corvette guys have run
bigger tires on the front. Your note seems to imply you
believe this, too, but there have been other notes that
seem to imply you have to match what was on the car
in the showroom -- not true, says I
Not that it's anything other than my opinion, but there it is...
Jerry
Jerry Mouton mailto:jerry@moutons.org Laissez les bons temps
rouler!
----- Original Message -----
From: "Mike Eynon" <stingray@onth.com>
To: <ba-autox@autox.team.net>
Sent: Thursday, April 26, 2001 1:56 PM
Subject: M3 tire question
> I posted a half question yesterday about this, and got no definitive
answer,
> so I thought I would post it again stated a little more directly.
>
> <BTW, thanks for all who responded to yesterday's mail>
>
> I want to run a set of racing tires on my '98 M3, and no... I really don't
> care about losing my novice standing (Playing with the big kids is how I
> improve the fastest). I have taken the list's advice and gone in search
of
> Kumhos. After the comments yesterday, coupled with a little more of my
own
> research on the web, I agree that these are likely my best choice right
> now... but what size?
>
> Right now I am running the stock staggered setup -- 225/45 R17 in front,
and
> 245/40 R17 in the rear. Kumho actually makes both those size tires with
the
> exception that the 245 is a 245/45 R17, and I do plan on getting 17 inch
> rims for my race wheels. Enter my dilemma...
>
> The way I see it, I have 3 options --
>
> 1. Get the same size tires that I am running now. These are sure to fit
> without damaging the car, but they come with the same problems that I have
> now... mainly that I cannot rotate them.
>
> 2. Get 245s all around. This sounds great, but I am not sure that they
will
> fit. Besides the extra width, the Kumhos are about .6 inches greater in
> diameter... and I don't have all that much room under the front wheel
well.
> I would definitely need to talk to someone who has direct experience with
> this before doing it. The last thing I wanna do is have to send 2 wheels
> back, or have to sell them myself.
>
> 3. Run 225s all around. This sounded funny to me until my friend pointed
> out that the tread width on the 225 Kumho is nearly a half inch wider than
> the tread width on my 245 Potenza S02 PP street tire (according to the
> TireRack tables).
>
> Anyone...? I was hoping to get this figured out in time for the next race
> down in Marina (2 weeks) but unless someone has a solid recommendation, I
> may be waiting a little longer. My prefered (if I knew they woudl fit)
> woudl be 245s all around; but right now I am willing to settle for the
> staggered setup.
>
> // Mike Eynon
> // Chief Technology Officer
> // OnTh Wireless
> // "The Wireless Database Company"
> // 1366 Bulb Ave
> // Santa Cruz, CA 95062
> // stingray@onth.com
> // 831.588.2388 (cell)
> // 831.621.9402 (voice mail & fax)
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