mdrambler, to assess air conditioning efficiency, one must also know the temperature of the room/vehicle air being taken in (either recirculated inside the vehicle, or the outside air temp. if you turn off the recirculation feature). I don't know what the design goals of vehicle A/C are, but a net drop of 30-40 degrees F. might be all that can be expected between the intake and output temps. IMO.
If the A/C's intake air is 80, for instance, and the design capacity is for a drop of 30, then that nets out at your 50 degree output air (until the intake temp. drops more).
That is the range of my insight into this FWIW, but you might want to assess the intake air temp. next.
2015 XLT 150 Wagon, 3.5EB/3.31LS, 130" WB, low roof, 8-passenger, full trailer tow incl. brake controller, ordered 12/14, delivered 4/20.