ok..so lets start by saying Yes, i am cheap!

I am looking at a set of 35/13.5/18's that i can get for a great deal..... but i want to be sure i can put them on my Sahara with spacers.....

i have seen posts with 35's stuffed under a stock sahara and saying its ok unless overloaded or offroaded..... i will get a lift before that!

these are the tires:

Pro comp X Terrain
325/65/18

Im thinking spacers of 1.5 - 2" ?

 

I'm putting 35's on my stock sahara's too.. but 12.5 wide is pushing it but alot of members run it with no problems, and I think 13.5 will be to much. the stock Sahara wheel is 7.5 inches wide, and according to below, 10.5" would be max.
One option is to get some cheaper (or save and get some good ones - AEV, ProComp) 16 - 17" wheels that are wider, and spend a little less on tires (smaller the size = cheaper the price)

Quoted from another post-----------
Most industry experts recommend 2-3" difference for wheel width/tire width. The section width of that tire is 12", so by going with what the industry experts suggest you should use a 9-10" wide wheel.

Hope this helps !