Hello again i have another question.So i just installed new 225/75/15 tires and i was wondering was is a good psi for on and off road driving?

on the xj, my opinion running practiaclly every tire availabke in stock sizes is that 28 to 32 psi is good for on road...offroad, 15 or so to not break a bead....can go lower if careful.

my door placard says 33 so thats what i put in and cant complain

33 to 35 for me.

My '97 calls for 33,,,I am going to try 35 and see how the tread does.

might start getting into the territory of a really hard ride. If roads around you are really good then you may not notice it as much....but if you hit crap ones like most of the country has, then they will bounce off of everything.

I believe the "rated" pressure is for p-metric radials. If you've switched to a higher ply light truck tire as many of us have, you likely will want to lower your pressures some. 30-32 psi is a good starting point for LTs, IMO.

I run around 28 psi my 31x10.50x15s.