OK, I have some pressures, as measured on the hose bib on back side of house (water comes in from front of house):
Static: 48 psi
Kitchen sink running: 40 psi
Kitchen sink and bathroom sink running: 24 psi!
Kitchen sink, bath sink, washer (warm fill): 6-7 psi !!!!!
Washing machine only (warm fill): 16 psi
Front spigot only: 26 psi
Front spigot and toilet flush: 16 psi
The house is a 2-story. Outside hose bibs are (obviously) on first floor.
Hopefully this provides some usefull information?