very usefull tyre size calculator

[gtsnissanb]

found this earlier dont know if its already been posted
it has lots of usefull information on wheels and tyres but most importantly has
offset calculator
tyre size calculators tells you what the speedo difference is
An ideal rim-width calculator
http://www.carbibles.com/tyre_bible_pg4.html
have a look sorry if its a repost(Y)

 

[RTLkyuubi]

This site created by a friend of mine is much better at calculating offset and speed differences:

http://www.willtheyfit.com/index.php?