An important feature of the SmarTire Full Function Display system is that pressure deviation alerts are initiated from a comparison of the temperature compensated pressure to the measured tire pressure read by the sensor.

The reference pressure, or COLD PRESSURE is the air pressure inside the tire inflated at room temperature 18°C (64°F) to the vehicle manufacturer’s recommendation. When a tire heats up, the air pressure inside the tire can also be expected to increase. For example, a normal or "required" pressure at 64°F or 18°C may be 34 psi (2.35 Bar) and a normal pressure at 49°C (120°F) may be 39 psi (2.7 Bar). Both pressure readings are correct at their respective temperatures.

The amount of deviation from the required pressure (at any temperature) can be read by using the Pressure Deviation mode of this SmarTire product. If at any time you are uncertain that the Actual Pressure reading on the display indicates the correct tire pressure, switch to the Pressure Deviation (+-) readout. A blank display indicates that the reading on the display is the correct one. Any (+) or (-) value indicates the tire pressure is incorrect by that value. This value can then be used to correctly inflate the tire.