Wheel Dimensions

[Kawan]

Hello folks,

 

I am trying to learn more about the dimension of rim and tyres .

 

1.

Only know that my rim is 17" and my tyre is 215/45R17. How can i find out additional information such as the "offset", and whether it is 7" or 7.5" etc (without asking the shop)?

 

2.

I found the website for my rim which mention the rim size "1770 +50 215/45R17" is meant for my car model. What does 1770 and +50 value represent ?

 

3.

How can i find out what sizes of tyres can fit my rim?

 

Why can't they just explain with a drawing instead of writing description like

http://www.mtdealer.com/t_inside.cfm?actio...et&storyID=1190

 

Thanks for any reply.