Originally Posted by TTT
Point taken. I can also bring some physics into this... now, you also have to remember that most of physics, especially basic physics, is for 'ideal world' applications. F = f * N is the equation used to determine the amount of friction. This equation means "The frictional force is equal to the frictional coefficient times the normal force." Contact area has nothing to do with this equation.
That's correct. But the constant f is usually function of material and geometry, so it is not constant between two different tires.
I still stand by my answer, I thought about it some more. I think the wider the tire, the less likely it is to deform unfavorably, which contributes to increased f and increased traction.