This may be common in other cars, but I know that my '05 Hyundai Sonata specifically states the mfr-recommended pressure as 30 psi under normal loads and 33 psi under heavy loads... and the tires on the car (put on by the Hyundai dealership after they got it as a trade-in, so I assume they're cheap but of the appropriate specs) are only rated at 35. Even in normal use tire pressures will sometimes be more than marginally (which I'll define as 2-3ish psi) greater than even the sidewall rating. To use Hobbit's example, if I were to put 33 psi in my cold tires in VT, load the car up and drive down to Florida, my (warm) tires could potentially be ~40 psi, 15% greater than the sidewall and over 20% more than the mfr's recommendation. Add in to that as well that my tire gauge and/or compressor might be off by a few psi. The consensus here seems to be that the lawyers and/or engineers have such scenarios and deemed that such an occurrence would be safe, or at least not deadly enough to make tort lawyers salivate (which, given lawyers, means "very safe" to me). Thanks gents. This has turned into a very productive, friendly, and helpful thread.