A/C Pro

What is Ambient Temperature and what should my pressure readings be?

Ambient temperature is simply the temperature of the air surrounding the car. The following automotive A/C chart outlines the proper pressure readings for a particular temperature range. For instance, if the ambient temperature (outdoor  temperature) is 75°, the corresponding low side pressure should be between 35-45 psi and if needed the corresponding high side pressure would be between 150-170 psi.