| Tire pressure depends on the individual tire you put on the wheel. Read the sidewall for max pressure and put in about 3-5 PSI less than the max rating.
During the winter, put in 5-6 PSI less than the max tire PSI (while the tire is cold. Once you start driving the car in the winter, the tires will heat up, pressure will increase, and you will reach the correct tire pressure)
The goal is to give your tires a level footprint, so the tread wears eavenly and weight is distributed eavently - which translates to better traction & longer treadlife.
You may want a staggered pressure setting, less in the front, more in the rear. This depends on weight distribution on your car, driving style, alignment and other factors and can yield better traction during turns when the weight is shifted to one side of the car, increasing pressure in the tire, etc etc. This is up to your own experimentation.
The book is for the stock tires that they put on the car (not specifically wheelsize, but that is a factor) and a generalization.
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