If you want to check the tyre-pressure, you can use spreadsheet I made, in wich I use the same formula as the European tyre- and car-manufacturerers use to determine the advice pressures.
Recalculating tyre-pressure - Windows Live
in this map the spreadsheet and an example spreadsheet with 2 pictures of it. In the first apearing schreen when you open the spreadsheet, the asked data are mentioned.
And sorry for miss-spellings and the use of wrong words, it is a translation from my native speek Dutch. Give me the correct words and spellings if you find wrong ones.