what the lightest 15x9 inch rim is, that will work with the jk with no spacers etc... I want to buy a set of 15's but i would like to get the lightest one possible. Also, what are the requirements for a 15' rim to fit? I understand some fit and some dont, why?

 

Any aluminum 15" is light. A 15" wheel must have less than 4" of backspacing. This is so they will clear the brake caliper.