Here's another good link:
http://www.carbibles.com/tyre_bible.html

Note: There are 4 pages of info here. The other 3 pages are
linked at the bottom of the first.

How to measure and understand wheel specifications

To complement the last post tire specs too…

tirerack.com/tires/tiretech/techpage.jsp?techid=46

The 91S represents the tire's Service Description. A Service Description identifies the tire's Load Index and Speed Rating. Service Descriptions are required on all speed rated (except for Z-speed rated) tires manufactured since 1991.

Hope this helps…

This is a goodn.....
http://www.willtheyfit.com/index.php?wi ... 20#content

Hi guys just sogned up,
Ive just purchased a 04 ba xr6t ute, its tub not tray!
Ive just had fuel pump injectors valves exhaust +++ = 370rwkw.
Im still running STD 17x8 wheels and wondering what i can fit on the back..255-265/40-45. Need it sorted asap as i cant get traction at all when boost hits.