I have a '96 XJ cherokee with crappy steel 15 X 7 rims
Will the larger 16" wheels from newer Jeeps fit?

 

The stock tire is a 225 X 75 X 15

What is the WIDEST tire I can get without hitting the frame when I turn the wheel all the way to one side?

 

Probably 235's with stock height.

 

Thats it?

What if i switched to 16" dia wheels from a Liberty?
Would my speedo read incorrectly or does it drive off of the trans....ie, no difference

 

It'd be better to get 16s or 17s with closer to stock sized tires than 235's on 15s (which is what I'm doing) - can definitely lead to wobble issues, but thats just my .02

Your Speedo should still be fine, but even if it it isn't, who cares? It'll only be off my like 1mph. Mine is low by like 2mph, and I'm pretty sure it's cuz of the oversized tires.

 

235/75R15 (9.25" wide) is the biggest you can fit without rubbing or trimming - your speedo will be off but only by a very tiny amount


you can put 16s on - here are the choices that should fit (and are wider than stock)

235/70R16 = 29x9.3R16 +0.3%
275/60R16 = 29X10.8R16 +0.3%
255/65R16 = 29.1x10R16 +0.7%
245/70R16 = 29.5x9.7R16 +2.1%

 

I've got 265/70/16 on my stock height '88 XJ, and on a somewhat sagging suspension and they don't rub on the body...although just barely. I will be lifting it as soon as I can afford it though. If you plan to keep it stock height, go for less than 255/70/16.