[Christ]

I gather that traction is a force generated on a surface by the weight imposed on a section of that surface.

I also gather that increasing tire pressure generally makes the contact patch of rubber to road smaller, but increases the downward force load (weight) per square inch.

In other words, if you put 100 lbs on a square inch of rubber, you've got 100 PSI of force pushing you to the ground.

If you increase the pressure of the tire sufficient to decrease the size of the contact patch, then you increase the point load on a smaller section of the tire, either maintaining the same PSI rating on that section, or increasing it. In all reality, since the change in contact patch is the only variable, the pressure per square inch should actually rise, in comparison to the amount that the contact section has shrunk, proportionately.

IOW - If you lose 15% of your contact patch, that's 15% less area to support the same weight, thus, the weight forces the remaining 85% into the ground harder, creating a higher friction coefficient between the tractive surfaces.

I guess that would be the definition of equilibrium...

The caveat is that the less tire that is in contact with the road at a time, the less hysteresis losses there are, and the cooler the tire can run, since the ratio of cooling rubber to heating rubber is changed positively.