Like Bob said, you just cant compare auto a/c with home a/c.
Anyone who says different just doesnt know any better.
Home a/c is a ~20 degree split.
TT roof air is also a bigger split than home a/c.
Auto a/c is designed to cool down to just above freezing at the evap and then cycle off from the low pressure cycle switch. This is due to some people living in more humid areas and we dont want the evpa turning into a block of ice, blocking airflow. Most cars with good running a/c should see ~40 +/- 5 while cruising down the highway.
I can get away with my adjustable cycle switch in my truck because we dont have any humidity most of the time. It can blow 25 degree air on high which means the evap is more like 18-20. In july-aug when its humid, I adjust up ~7 degrees.
ASE Master tech for 1/4 century, IMACA a/c certified so Im not just posting crap.