Originally Posted by
FBinNY
This reflects two criteria. The higher is based on the tires internal structure, and the second to the bead's loss of holding strength on a non-hooked rim.
I fully understand.
The wider tire should take less PSI to provide the appropriate support, which is why width is important in this scenario.
I guess the 30 and 32mm tires are maxed at 72psi, but I'll agree with the OP that it seems low for a hooked rim installation.