Tire contact area

["Scott Payne" <sppayne@xxxxxxxxxxxxxxxxxx>]

All:

I have a tire size calculator that will help with this discussion.  What
sizes do you want the contact patch for?

On my car, the 96' 328i here is what I calculated for either the stock e36
sport package setup with 225/50/16's or the M3 setup with 235/40/17's.

225/50/16 -
Height 24.8582"
Sidewall 4.4291"
Width 8.8582"
Circumference 78.0944"
Revs/Mile 811.3247


235/40/17 -
Height 24.4015"
Sidewall 3.7007"
Width 9.2519"
Circumference 76.6597"
Revs/Mile 826.5092"

Now I will throw in my .o2....  I think you will feel a tire compound
difference much better than the sidewall height/width difference.  

The tire size calculator is available for free to any Palm OS user.  Look
for it on the zdnet website.

Scott