I know of someone who has some connections in the tire industry and had some interesting things to share on max pressures. For obvious reasons, he wouldn't tell me the manufaturer or the exact pressure, but did say that a tire was inflated to "well over the 200 psi level" and didn't burst.
He has driven on tires that were pumped to 120 for a short time. I think krousdb knows who I'm talking about.
I am currently running 60 psi in my Goodyear Assurance Comfortread's. The max pressure on the sidewall is 44 and I have seen no odd tread wear patterns after nearly 5,000 miles. The same tires on my son's car(formerly "my temporary ride") have nearly 10,000 miles and no wear problems. He has let his tires drop to just over 50 psi.
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