[snowwy66]

Maybe not recommended but would it be bennificial for fuel mileage improvement during colder months? Truthfully vehicles defrosted windshields for years without A/C

only think i woildnt like about the unplug would be no use would allow the seal in compressor to dry up and fail. So if unplugged all winter long you may end up replacing compressor in the spring.

And you just answered your own question on that second line. And it's not just the compressor with seals. Everything ac related in your car has a connection that involves seals.
The compressor is tied in to the defrost so that it gets occasional use to keep everything lubricated and functioning come next year. Otherwise, think of the massive increase in ac repairs.

Supposedly it also helps to dry out the moisture on defrost. Those of us on the west, only have moisture when it's raining or snowing. Or frost. Or whatever. As compared to the east coast where it's almost always humid.
Us westerners really wouldn't notice the moisture dillemma the easterners have.

 

[snowwy66]

My first car, a 1984 model year, ran the A/C whenever the defroster was engaged. So it’s not a new function to me - or GM.

67 olds

 

[snowwy66]

Of course it did. If you want to quickly clear a fogged up windshield, turning on the a/c is a no brainer as it dehumidifies. I am seeing all these misguided fools that think they should unplug the compressor in the winter to save 5 cents. I am amazed that people are that clueless. My 2015 Cruze LTZ has automatic climate control and I leave it set at 72 degrees all year round. It keeps the cabin comfortable and I don't have to deal with minutiae.

But some people are certain that they are smarter than everyone else. They are the micro-managers. No one likes micro-managers.

BAck when smog pumps were around. Before the carburetor got replaced with fuel injection. It was common to leave the belt off. MORE POWER SCOTTY. Some went so far to pull all the diverter valves off. Then beeched and moaned because it won't pass emissions.