pound force per square inch
Pound force per square inch (psi) is the pressure from a force of one pound-force on an area of one square inch, which is about 6,894.76 pascals. Car tires in the United States are typically inflated to 30–35 psi.
Inches of water
Inches of water (inH₂O) is a pressure unit from the Imperial system. An inch of water is defined as the pressure from a one inch column of water at 4°C (39.2°F) (which is the temperature at which water is densest).