Carrera 3.2 A/C Outlet Temp
The definite "number" would be the difference in evaporator plenum inlet air temperature vs the outlet air temperature at the same low blower speed for both.
Assuming your system was perfectly charged, everything was running perfectly, you can expect
'about' 35 degree difference between your vent temp and the outside air temp.
In some cases the difference might be slightly better or worse. There are many variables (once again with a perfect system) such as the color of the car (dark colors are harder too cool than light colored cars), the number of occupants in the car, the speed you are driving, if the car has sat in the sun on a warm day it will take longer to cool down, fan speed 1 makes colder temps than fan speed 3 however the volume of air is less on speed 1, etc.
Good reading material here:
http://www.griffiths.com/porsche/ac/ice/index.html


