Signed in to give you information about calculation of tire-pressure.
Found this topic when googling for tire-pressure.
I live in Holland and in 2007 got hold of the system the tire manufacturers in Europe use to determine the advice-pressure for radial tires, and worked it out.
Learned myself Excell to make spreadsheets for it. In 2009 I discovered that this system, as I thought was was worldwide, was diferent in Europe and America.
The basic Equation is the same, but the power used for calulating weight for a sertain pressure was diferent up to 2000, from 2005 for normal car tires it is upgraded in America to the European one. Found an article about a new suggestion of calculating, in wich the indentation of the tire stays the same at a lower load then the maximum, and comparison with the since 1928 used universal power Equation,and its diferent powers used.
I am now busy making my own system based on that article wich comes to higher pressures, so always is saver then the power-equation ,even of Europe, wich is reasonably save for normal and reinforced car tires.
collect the asked data in the spreadsheet in the next map, and fill in . Then you get advice for normal use ( 3 persons an a little load, given in Europe, up to 2000, but not in America) , for Heavy load ( using the Gross axle weight ratings, and now called normal for 4 persons and load) and for vacation load( over- or uneven loaded rear axle, mostly when towing a trailer), and those 3 for up to 160 km/h and up to maximum speed of car).
recalculating tire pressure
The article you can find here
and is in English.
From these links you can navigate my complete public map of skydrive wich belongs to my hotmail adres with the same user name as in this forum, so combine it and you can mail me for questions, or give me a personal message here
At last, to my opinion the changes made in the system between 2000 and 2005, are not coincidentialy parallel to the Ford/Firestone affaire .
Greatings from Holland
Peter
