[UFO]

Originally Posted by JacobAziza

Most of my experience is from bicycles, so it may not be a direct comparison. It may not be relevant at all.

Running any less than rated sidewall pressure (on a bike) gets you a slight decrease in ride bumpiness (slight enough to be irrelevant if you have suspension) at the cost of not only more rolling resistance, but also noticeably worse handling.
This is because if the tire isn't stiff, it flexes a little in the corners.
Further, unless traveling on loose dirt or mud or snow, having low pressure does exactly zero for traction and braking.
I consider the number on the sidewall to be THE recommended pressure, not the maximum.

I don't remember who it was, or what the post topic was, but somebody on this forum once claimed that high tire pressure does not in fact adversely affect braking distance (on a smooth dry surface) as is commonly assumed.

AFAIK the biggest reason not to exceed the sidewall max is that the tire and/or rim is only so strong, and if you go over by enough it can literally explode. For the purpose of avoiding lawsuits, the manufacturer picks a number well under the actual maximum a rim/tire can handle.

Not that I ever drive at the limits of the tire's ability, but I haven't found running high to have any adverse affect on braking or handling or tire wear on my motorcycle or truck.
I run the truck at 85-90 (rated at 80)

Bicycle tires have a round profile and do not have any structure. Their sidewall pressure rating IS the recommended pressure; you are correct, lower pressures increase rolling resistance because you increase the contact patch due to no tire structure. Car and truck tires are completely different, and the sidewall pressure rating IS the MAXIMUM rating.