The more rim and the less side wall=the less squish. With low profile tires their side walls have less flexiblity because they are thicker.

Lars

Oh yeah, I guess I'm just used to 15-17 inch rims where there is larger differences in squish. Haha I've also never even seen someone with winter tires so I couldn't pick one out if it was an inch from my nose. :hehe: No need for snow tires down here in central south texas, we either have dust, mud or ice (ranked in most common). We also only have ice for about one or two weeks out of the year, leaving just enough time for people to wrap their cars around trees and telephone poles. I dont even count anymore how often I hear "well I could drive on the ice back home no problem." :shrug:

Yep you got that right about the weather down there!
I have played down there and worked there too!
Best thing I have learned in any of the soutern states and ice is just stay off the roads! It's more comical to watch people drive on that stuff than anything else. I guess no matter where a person lives it's just plain good common sense to stay off the roads when they are icy!

Lars

Well while living in the south I found out that truck tires may slide very well but bike tires do not. My back brake lines froze so I was going on just the front when everything just happened to grip and that front gripped enough to send me over. Ice hurts. :rofl: Ice has traction, its just when you dont want it. :hehe:

ballistmike - sorry to get in on this so late, but I've been away.

If you change tire sizes during the year, I would NOT get specific tunes for each tire size. Just get tunes for the kind of driving you do, like "towing", "highway", "around town", whatever; and, tell Bill the tire size you have on the truck throughout MOST of the year (which I suspect is your "summer" tires). Then, he'll put that tire size into your tunes and you won't have to adjust anything.

In the winter, when you change tires, it's a simple matter to go into the "Custom Options" menu and change the tire size. Then when you remount your summer tires, simply reload your tune without any custom options - your tire size will be correct again.

And, as Lars was telling you, as long as the TS and GR are correct when you tell the Gryphon to program the PCM, the shifts will happen when they're supposed to, no special tune is needed.

- Jack