This pic shows the temperature out of the air vent and in the car

Note the 27 degrees difference. This is an R12 system still. I wonder if the the newer refrigerant gases can do as well .
The outside temperature was probably the same as in the car. I noticed that if the speed dropped below 40mph then the air vent temperature crept up a bit until the speed picked up again.
This system gets the air temperature down to around 1 degree when it is not so hot. So it must have been working flat out today as it could only cool the air down to 5 degrees.
Does anyone have any figures to compare ?