Rim width question

[dirtrace09]

I see that IMCA Late Models run a 12 inch wide wheel while most others (such as UMP,etc...) run a 14 inch wide wheel. What does this do to the width and performance of the tire? Can you tell a difference in grip and such from one rim width to the other? I have never driven a Late Model so any information is appreciated.

[C10]

the 14 widens the contact patch giving more grip pretty much all around. The 12 inch wheel they have us on makes the tire look like a rounded floater tire and really takes away side bite. I wish they would give us a 14 inch wheel, I think it would make our tires last longer.