You are radically compromising traction by running hard.

Tires these days are made to cover a lot more types of vehicles with
better sidewalls than yester year.  You can still get the cheap tires
that only allow 35 psi max, but you get what you pay for.  These tires
can/should only be used for light duty.

The 'proper' inflation for your 'vehicle' gives the best footprint on
the ground with a compromise to the hard side for a bit better gas
mileage usually.

The footprint is the important part.  Off roaders typically use
oversized tires so we have to find the correct pressure for that good
footprint.  One method we use is the 'chalk' method.  We run a bunch of
chalk marks across the treads and drive slow in a straight line a
little, then look to see how much chalk is left.

The best footprint will leave about 1/2" of chalk on each side.  A bit
of gas mileage compromise gives about 1" at the most.

When I got my latest tires, BFG 33x9.5" mud terrains, the shop left them
at the installation pressure of about 38 psi if I remember right.  I did
the chalk test and only had 3.5" of tread in the middle of the tire
touching the ground!  Less than 50% of the tread width!!!  I dropped it
to 28 psi and got the best footprint, then upped it to 30 psi (32 for
loaded highway) for mileage and in my case a stiffer sidewall.

If a short wheel base vehicle like a Jeep Wrangler runs hard tires, they
tend to do 180's and 360's with no warning on on/off ramps in the rain.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Mbflash <mb6467@worldnet.att.net> wrote in article
<VPFme.266619$cg1.108920@bgtnsc04-news.ops.worldnet.att.net>...

I'm sorry, but I simply cannot imagine a '96 Taurus serving as a reliable,
adequate, technically irrefutable, test platform for accurate tire pressure
evaluation.

It all depends on the tire design. I have had tires on the front my 92 Beretta that wore as if they were overinflated with 30 psi. I have also had Continental tires that looked like they were underinflated with 40 psi. And yes, the Continentals with 40 psi have excellent handling.

Two problems.

1.  Excessive tire bounce of over-inflated tires will
    shorten the life of your suspension components.
2.  The tire patch (the amount of tire contacting the road)
    will be significantly smaller, compromising traction when
    you most need it.

Use ONLY the manufacturers recommended pressure in the tires.

My thoughts are run the door jam pressure, independent of the max on the
tire.  Reason, we are talking PSI (pounds per square inch).  If you exert 1
psi on a 10 square inch area, you get 10 pounds of force.  Same if you put
10 PSI on 1 square inch of area.  My thinking is take each wheel
independently (say 4000 lb car evenly distributed so 1000 lb at each wheel).
At 0 PSI you have the side wall holding the car up (but not very far).  At
10 PSI you lift the car some (side wall support + 10 PSI acting on some
effective area).   The area is large as a lot of the tire is touching the
ground at this point but it is supporting 1000 pounds.  As you add air, the
pressure goes up and the area goes down still supporting the same weight.
If you have the pressure in the tire as recommended on the door jam , you
have the contact area and ride height set to what the manufacturer suggests.
There may be some difference in brands as sidewall still support some of the
load but I assume little difference.

If you change tire size or rim size, the door jam numbers no longer apply.

Just my "Tire Pressure Thoughts"
bb