Rims and tire
 

I did some research and came up with the biggest tires on a stock Cherokee is about 30's with out rubbing. I got 17" jeep rims on mine. My logical thought would say my biggest I could run would be 28" since my rims are 2" bigger. A I totally wrong thinking this or can I still get 30" on these

This is all with out any lift on the xj

You can still run a 30" tire. Tire height isn't affected by rim size. A 30" tire for a 15 is the same height as a 30" tire for a 17.

If you don't mind trimming you can run higher than 30s. I ran 32s stock and HeavyMetal on JF ran 33s on one of his builds stock and ran through everything at Rausch Creek like that.

Even with 30s you're going to rub turning and don't want to go offroad with them.

For a 30" equivalent on a 17" rim your gonna wanna get 245x65r17 tires. its kinda an odd size but there out there. its a suv size so youll only be able to find street and mild A/T tires.

http://www.tirerack.com/tires/TireSe...65&diameter=17