Sodeti

Hi Guys,

Is it normal for the AC to be always running when the vent position is set to top position or top and feet, but not front or front and feet?

I noticed that as long as I select the top (defogging vents) the air is cooler, hence I think the AC is running...

Also, can anyone say with confidence that fuel economy is worse by a great margin due to using AC in the 350?

SGMIS3

If you select the windshield vents (defogging vents) the A/C is automatically activated. It is also activated when you set the circulation on auto.

Bichon

Yes, any air distribution position that directs air to the defroster slot will activate the A/C compressor to prevent fogging the windshield.

The IS has a variable displacement compressor that reduces the hit on fuel economy and performance when the heat load is low. Still, I've observed that I generally get 1 or 2 MPG better fuel economy when the A/C is switched off.

vdubturbo

Hmm, good to know. Eases my concerns a bit about being wasteful.

PMok

I started leaving my AC on all the time about a month ago, to see if it gets rid of the smelly AC condensor problem whenever I turned it off ... sure enough it works, and I have not seen my MPG go down at all... still seems to be about the same as before. So it seems to me like it was designed to be more or less left on all the time.

VF84

u just need to leave the circulation off when u turn off the car, rather than leave it in recirculate mode

Sodeti

Thanks guys. This forum proves its value yet once again.