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.
mm of mercury
The millimeter of mercury (mmHg) is pressure unit traditionally used in meteorology. It is the pressure from a 1 mm column of mercury at 0°C under normal gravity.