Ambient temperature is approximately 75 degrees:
What should the psi be on the low pressure side of the a/c as well as the total R134a and oil capacities? The a/c is blowing cold and it's holding at 35 psi after adding 1/2 can of R134a. The reason I ask is because it was blowing cool but not cold air on either outside or recycle switch settings.
Most general information I've found is based on psi at a given ambient temperature which is stating at 75 degrees the L/P side should be 35-45 psi. I'd feel more comfortable knowing what the General Motors recommendation is. If 35 psi is considered acceptable even if it's at the low end, I'll accept that answer.
Also, the a/c sytem has never needed servicing or the need for refrigerant since the car was bought new.
Personally speaking, it needing 1/2 can in eight years is pretty good!