Just as a personal preference, I like to have the floor and windshield on for heat in the winter and cooler months. I don't care for the vents blowing hot air straight at me.

 

If it's cool enough where you don't want A/C, it probably isn't going to run for very long anyway.
once the evaporator gets down to a certain temp. there is a thermostat that acts as a kill switch to shut the compressor off.

So, just try not to think about the A/C running... think happy thoughts. All will be well.

 

Fortunately, AC systems nowadays are fairly efficient compared to decades past. Not so much horsepower/mpg robbed. At least that was my understanding.

Would be nice to have the option I suppose, but other than maybe a slight HP/mpg savings, I do not understand why it is a big deal.

 

It's been that way for at least over 20 yrs. Yes, the older vehicles do have a decreased defrost capability. I remember my old GM, Ford and Chryslers would take awhile to properly defrost and they told you in the manuals to crack the windows to defrost the rear glass when you didn't have a rear window defog. The urban legend is that you lose a ton of mpg when you run the a/c. The reality is you might lose .5 mpg if you have a good head wind otherwise you really can't detect a difference that's not attributed to something else. Crank up the A/C.

 

Every A/C vehicle I've had turns on the compressor for defrost. On my Ford light trucks, the compressor only comes on when the outdoor temp is above 45 F. Or is it below? Anyway it depends on the weather.

 

In the old days, pre a/c, defrost/defog meant heat on the windshield. Interior fog was like ice outside so there was no way to remove water vapor unless a window was cracked open. Try to defog a 63 ford windshield in Mississippi on a July morning without heat. Ever drive an army M880 with a foggy windshield? Rejoice that a/c works.

 

The AC compressor does not change your gas mileage that much. If you worry about that little of a gas mileage change you might want to think about another daily driver!!

 

I totally agree, is fucking retarded even the dial setting for my feet only also engages the ac... I'm pissed I froze my ass off this morning on the way to work

 

Did u have the dial set to heat or cold

 

Heat all the way clockwise