Is The Factor Of Gettin More Expensive Tires Or Does Getting Bigger Rims Decrease The Level Of Performance?

 

Larger rims are generally more $$ than rims of a smaller diameter, the larger wheels are also heavier than a smaller wheel. The weight of the larger wheel is usually offset but the decreased weight of a small tire, however. The main issue with larger wheels compared to a smaller diameter wheel is they decrease the amount of sidewall you have on your tire. Too little sidewall and when wheelin your tires will not have enough flex to handle the terrain which leads to a harsh ride. Too much sidewall can be bad as well. Too much sidewall and when aired down your tires will not be very responsive and can be troublesome when off camber. A general rule of thumb is to keep your wheel diameter at about 1/2 your tire size i.e. a 17" wheel with a 35" tire. Some folks will comfortably run 15" wheels on 35"+ tires. 20" wheels on 32" tires are for mall crawlers not wheelers.

 

What IMFletch said. IMHO, 18" or larger is too big of a wheel unless you are thinking about going 40's or taller. With 35's or 37's, I would recommend going with a 17" wheel for the reasons stated and 16" wheels if you're only planning to run 33's. Another factor to take into consideration is that the brake calipers are large on the JK and a lot of 15" wheels will simply be too small to clear them. From what I have seen, there have been a few 16" wheels that didn't clear without some minor grinding of the calipers too.