Does it help mpg, hurt mpg, or have no affect whatsoever on the Vue GL's performance?? I've been using it a lot more cause I think it helps heat up the cabin quicker, but may I'm an idiot for thinking that?

Anyone ever test this, or know for a fact which is better? Obviously you want it on if you got a tailpipe in your face, but otherwise, what's the general opinion for those who use their heater or air conditiong?

 

When I use the AC, I think it is better for mpg to run the recirculation so that the chilled air can be recycled back through the AC instead of taking in warm outside air.

When the defog or defrost is on, recirculation is disabled. The owner's manual has more information on this.

 

It probably helps (for the reasons SGL pointed out), but it won't allow the moisture in the air to evaporate and thus lead to foggy windows, forcing you to use the defrost, which disables recirc and runs the compressor.

We almost always use the vent/floor blend setting for heat, since it doesn't run the compressor, unless the windshield is really foggy. If there's just a little haze, I just turn the airflow to defrost but keep the fan switch off, since there's usually a very small flow of air at all times. That usually does the trick without running the compressor.

 

I have always used the air recirculation with the A/C. SGL is right about that the chilled air can be recycled back through the AC instead of taking in warm outside air.

And I have always used the air recirculation with the heater. Just the reverse - warm air can be recycled back through the Heater instead of taking in cold outside air. Yep, foggy windows can be a problem with the recirculation.

All the other times - I do not use the air recirculation. Air will come through the vents through the normal course of driving with the vent open even if the fan is not on.

As for running tests on mpg - I have not tried my normal route with the air recirculation on. My guess is that it would not make a statistical difference either way.

The five biggest factors in my view:
Temperature
Driving Style (which includes Speed)
Traffic
Terrain
Distance of Trip

Number six would be Tire Wear. My mpgs are better this year versus last and the other five factors have remained relatively constant. (Difference 35,000 additional miles on the tires = less rolling resistance.)

Lifetime Average 31.992 mpg 43,200+ miles
Since March 1, 2008 33.370 mpg 5,200+ miles

 

Funny thing about my vue hybrid, the recirculation doesn't work, although saturn tells me it does. But, when there's smells from outside and I use it, the smells are just as nasty regardless of length of time i keep the recirculation button in use! Never has any other vehicle kept outside smells contained in car after turning the recirculation button on. See my other posts and you'll get an idea why this is 100% LEMON!