Why wont the 205/45R17 or 205/40R17 fit stock wheels?

[KevinS]

I will be running a solo event in June. My Mazda 3 will need new tires before that event. I am looking into running the Toyo RA1 tire.

Looking at all the spec's, why is the recommended wheel width different on these tires...?

205/50R17 - wheel width 5.5" to 7.5"
205/40R17 - wheel width 7" to 8"

If Im staying with the same section size (205) and just changing the height (50 to 40) why would the minimum wheel size change?

Am I missing something?

Kevin

 

[tsunami]

not sure though remember the height change is going to change your speedo.


after thinking a bit could be because of the angle from the ground patch to the wheel with a taller side wall its less of an angle where as a narrower side wall has a greater angle therefore a different ground patch..?? really pulling at straws here but thats all i can come up with.

 

[KevinS]

OK thanks. Also...does any know how much negative camber I'll get after I intall a set of Eibach Pro Kit springs? I heard as much as 2 degrees in front and 1.5 degress at the rear...