235/75r15. this is my current tire size. my understanding is the 235 is the tires diamiter, and the r15, well, duh, even ive got that covered. what i forget is what does the 75 represent... i know its the height of the sidewall, but is it a percent of the diamiter, or what... i hate numbers...

 

Per a quick google search:

235 is the width of the tire in millimeters.
The 75 is actually a ratio, meaning the height is 75% of it's width.
And obviously the 15 is the diameter of the rim.

 

another exapmle of how google loves us.. thanks!!

 

ALSO! running 31's w/ only a 2"bb is a bad idea, right? unless i wanna rub alot...

 

Should be good

 

Bump stops!

 

how big a bump stop?

 

we cant see your xj in person, put the tires on there pull out the coils and limit it to where you want, its a preference thing not a right and wrong way.


anyways this is a little useful too for tire size


Tire size calculator

 

It means the sidewall is 75% of the tread width. Find that number, double it, and add the rim diameter to get the approx. tire height.

 

here is a nice little calculator that I have had bookmarked for years and still use often.
http://www.tyres1.com/Calculators.aspx