newFitOwner

When I use A/C, I typically set the temperature to the coldest (blue). Sometimes, that's too cold, so I dial it back toward the middle.

That got me wondering. Is the A/C actually working less hard and robbing the engine of less power? Or does the A/C simply work at one level of intensity, with the reduction in cooling achieved by enabling the heater?

lostforawhile

compressor is either on or off,

claymore

Yes it will help with fuel mileage. The compressor cycles on and off to keep the air temp in the range you set using that control so if you chose the lower setting the compressor will cycle less resulting in better fuel mileage. BUT it will be a small amount not sure if you could measure it by normal methods of calculating fuel mileage.

daveb91

doesnt the temp control also regulate the shut off valve on the heater core? Dont know about a fit but on my integra it does..

lostforawhile

yea if you put it on cold, of course it shuts off the coolant to the heater core. A lot of cars the AC will also run on defrost, I know the older cars had a specific button to shut off the a/c, the idea of the a/c running on defrost, along with the heat, is to defog the windows

newFitOwner

OK, so if I understand correctly, when the A/C is turned on, the compressor is on for more of the time if the dial is set more toward the blue end. Furthermore, if the dial is on anything but the most blue, the heater is also enabled to counteract some of the cooling from the compressor.

Does this pretty well describe all the things that happen when the temperature dial is adjusted?

claymore

YES.................. unless you set it to defrost position. In the defrost position even with the A/C itself turned OFF the compressor still cycles as he said to aid in removing condensation from the passenger cabin helping prevent fogging.

newFitOwner

Thanks.