I just bought my 07 IS250 a month ago with navigation. The dealer told me that I would never really have to touch the AC button or press the inside or outside air button.

I guess it goes off of the temperature outside and sets up the controls itself.

My question is why is the AC always on even in the winter! it's like 28 degrees in Chicago and I turn on the heat and it shows the AC button highlighted and the air is from the outside.


Is it a good idea to override it or just let it be? I hate smelling the outside(exhaust fumes) from the outside, but when I override it I notice my car gets fogged up pretty quickly.


Any suggestions to leave it alone or can I turn off the AC(maybe saves gas?)??

 

If you have your settings on to defrost the windshield, the A/C will come on because it defrosts more effectively while pulling air from the outside.

 

True - it defrost more effectively because the air is drier.

If you leave the air on recirculate in the winter, it will get too humid and will cause your windows to fog up. There really is no reason to ever manually select recirculate unless you want your AC to blow really hard, as it uses more power (and gas) anyways.

Just press "Auto" and select your temperature, the car will take care of the rest.

 

Correct... the A/C not only cools the air, but reduces the humidity level as well, which is why its on all the freakin time.

I've shut mine off manually in the winter and the windows fog up pretty quick so I stopped worrying about it.

FWIW, the IS's do use a variable displacement A/C compressor, which means that when they are under light load (e.g. winter), they put less drag on the engine and in turn use less fuel.

 

thx everyone! extremely helpful information

 

The dealer told me <-- dont trust whatever they tell you....