A/C on Rear Climate Control- Affect MPG?

[cdcrawford25]

I noticed my mpg seemed to drop pretty dramatically on '11 CX-9 AWD GT after leaving my rear climate control set to Auto ON at 75 degrees. I was wondering if this is due to A/C compressor being on at all times? Has anyone experimented leaving this unit completely off and testing difference in mpg? The control doesn't seem to have an option to be on with no A/C like the main climate control does. I would like it to be on becasue the baby is back there, but if A/C runs full time I may just rely on front unit to control temp in car.

 

[Rawyzf]

Good question, I would assume it would effect MPG. But I have not tried this. We use the front Unit to control the temp.

 

[cvandenhaute]

Most modern automatic AC systems use a compressor that is used at partial load or even totally off depending the circumstances, I think you can keep it on "Auto" at a reasonable temp setting (like 72, 73 degrees) without fearing for your mileage

 

[f8tlfiveo]

If your ac is on, its on.. There is 1 compressor for the front and back. So I would say no it shouldn't affect your mileage.