How much PSI, Up or Down can we run in our tires without hurting their structure? For example, I like a bit more PSI in the front and either, even or less PSI in the rear. In other words, if my door jamb label says...F:30/R:30 but for ride comfort I like...F:32/R:29, is this OK? Or, any combination of there or about! Another example is, I have a vehicle that states on the door jamb label...F:32/R:32 but, I like, F:30/R:28...Is this OK as well?