I see lots of various explaination to folks, particularly new ones, over what this button does. Correct me if I'm wrong (probably a very redundant statement)...The Econ button is only in play when one uses the A/C. When using the A/C, if the Econ botton is activated, the engine will auto stop at a red light. THe A/C fan will continue to blow but the compessor and engine has stopped (05 HCH). If the A/C is on and the button is NOT activated, the engine (and A/C) will continue to run while stopped at the light.
If the A/C is NOT on, the Econ button has no purpose.
I thought that even if the AC is off, when using any climate functions the econ button still needs to be on for the auto shutoff to work. Not sure though, I have trouble remembering all the complexities I read about in the manual when I first got the car.
Keep in mind that if you want to defrost/defog the windows, Econ will automatically turn off and the AC will engage and Auto/Stop will be disabled, (when the director switch is on defrost). But, if you switch the fan control to off and the director switch to defrost, you can still clear the windows without the AC being on. Just crack a couple of windows and you will get a nice flow of air across the windshield as you drive, add a tiny bit of heat to speed things along. (this was covered in a previous post). Also note that in colder weather, the AC will not turn on when using Defrost if the outside temp is below 32F. Hope this helps.
Yeah, i hate the fact that defrost automatically turns on the A/C and you have no other choice but to use it that way. In the winter time, when the heat is on, the air is already dry, there is no need for the a/c to engage. Real dumb.
So, the Econ button engaged provides for autostop when either the A/C is running or the Defrost (with fan on) is running. If Econ were not engaged, autostop would not work (engine keeps running). My point is that when this question comes up, I get the inpression that some think the button somehow effects other stuff. I am wanting to verify that it does NOT do anything other than provide for autostop to work even when airhandling systems would otherwise over-ride autostop.
As for those who never disengage the Econ button, Atlanta at 5:30 stuck in traffic 6 wide, mid-AUgust with 85% humidity and 92 degrees, its WELL worth the loss of a MPG or so (doesn't seem to be too much of a hit to me, I get on average 43-44 mpg on an 05 HCH with 10k total miles. Lifetime at 43.1).
the Econ button makes your car use less gas for A/C when you have the A/C ON and also allows auto-stops. if you have Econ button on and the A/C OFF, then the Econ button's only purpose is to allow auto-stops. but it is certainly possible to have the Econ button ON with the A/C OFF.