To quote Robert Duval "Tares is what wins races"

Its important to understand how those few inches of contact patch impact the dynamics of the car.

Below is how much tire is touching the ground on a 26x12 tire on a 10" rim at 30 psi. Out of a 12" section width tire, only about an 8x4" patch of rubber is actually on the ground. that's not a lot and if you are using something as skinny as a 235, this patch is even smaller.