33 pounds per square inch (PSI) is the answer. This is 2.137 bar.
I share this with you to save you the thirty minutes it took me to get the answer. Internet searches were failing me, tyre fitting sites like KwikFit and the board by the air line at the local BP garage all failed me.
So if you have a Jeep Grand Cherokee WJ 2.7 CRD Limited: pump those tyres, when they are cold, to 33 PSI. That of course assumes you are carrying a normal load and regular tyres e.g. 235/65VR17.