[s-cars] what is the optimum tire size for 17x8 wheel

[Dave Ellis]

Hmmm... I too am trying to decide between 245/40-17 and 255/40-17 tires. 

I was leaning towards a 255 tire until I checked the data sheets and 
found that both of the tires I'm considering (Dunlop SP8000 or Toyo 
T1-R) both list 8.5" as the minimum mounting width for their 255/40-17 
tires.  

Also, in a recent thread on Audiworld discussing tire widths a couple of 
posters described light rubbing with the car loaded down or when 
reversing when using a 255 tire (I'm guessing wheel offset will play a 
large roll here).

For the roads I have to drive on I have decided to go no larger than a 
17" wheel, but finding a 17x8.5 wheel is next to impossible unless you 
have deep pockets for something _nice_ like BBS or such.  So it looks 
like for now I'll have to settle for a 17x8 wheel.

While I would prefer to have a 255 tire, I don't want _any_ rubbing 
issues or to have to roll the fender lip or such.  I also don't want to 
risk compromising the mounting of the tire or the sidewall integrity by 
mounting a tire on a narrower wheel than is required.

What experiences have fellow S-car listers had with 
   -a 255 width tires on an 8" wide wheel?  
   -rubbing or contact issues with a 255 tire?
   -if you do/don't have rubbing with a 255 tire, what
    is the offset of your wheels?

I'm running Eibach Pro springs with Boge TurboGas dampers if that's any 
help.

By the way, the best tire calculator and offset calculation web pages 
I've found to date are as follows:

  http://gs.tolan-hoechst.com/tirecalc.htm
  http://www.miata.net/garage/tirecalc.html
  http://toy4two.home.mindspring.com/offset.html

-Dave
Ottawa, Canada
'93 S4
'99.5 A4 1.8t



On April 12, 2005 13:54, CaptMagu at aol.com wrote:
> s-heads
>
> Actually, 255/40-17, is the closest to the diameter of the stock
> 225/50-16. This size is also the stock size with the C5 A6 when you
> order 17x8 wheels and tires from the factory. I used to run
> 245/40-17s on 17x8 rims for summer but have recently switched to
> 18x8.5s. I still run 255/40-17 Victoracers for the track with SSR
> Comp 17x8.5s. As another data point, the actual width of 245, 255 or
> whatever size tire varies greatly from one manufacturer to another.
> Several years ago I mounted a set of Yokohama ES100s in 255/40-17 on
> my wife's A6 4.2. They were 30mm wider than my 245/40-17 Toyo T1Ss.
> HTH
>
> Hap, wit dakine tire info from Evahboost, Maguire