The electricity needs to be generated, and that puts an extra load on the ICE with a corresponding drop in MPG. If the ICE is not running, then the power comes from the batteries, which will deplete faster and require the ICE to run to recharge.

(add 'no free lunch' disclaimer here)

 

Quote: I can put up with a little temp change in the cabin if it saves on fuel, but since the AC is electric powered how does it affect the MPG?


Since the electric power is generated by the ICE and regen braking the AC will effect your MPG.

 

I've seen many ultra technical discussions on this topic, but I see it another way.
Unless I'm sitting in bumper to bumper traffic, I rarely, if ever, have the ICE turn on to recharge battery. In simple terms, my power (non-NAV readout) always varies between ~60-90%. Highway and local driving seems to keep the charge level well above the recharge level (~30%?).
Now, if I turn on the AC, I know I am using electricity, but based upon my very unscientific observation, the power level still stays well above recharge level. Sure, some power is being used, but I guess my car generates sufficient reserves to keep it comfortably charged.
In normal driving, I've never had the AC on and seen the car use the ICE to recharge.
There is enough coasting at highway speeds to make up for any power usage that takes place.
In other words...I think I'm getting a free lunch.
A fair analogy (although differing in scale) is the headlights. I defy anyone to show any difference in mileage due to the power used by the lamps. Yes, AC uses more, but it's never been (at least in my car) such a power drain that I've noticed the power meter as being depleted.
Does this make sense?

 

First a disclaimer. I don't know as much about electrical engineering nor the TCH powertrain.

That said, anytime you need to recover the electricity used, there is corresponding mechanical drag that is required to create that electricity thereby costing you fuel.

 

We went to visit some relatives on a warm day and found them not at home. A cell phone call found them 30 minutes out but on their way, so we decided to wait for them and sat in the TCH with the AC on. The AC worked on battery only for a long time - like 25 minutes - and we saw the battery gage on the instrument cluster get down to just a few bars before I got concerned and drove the car a mile or two to recharge the battery.

Would the ICE have come on by itself or could I have fully discharged the battery? I wasn't sure and didn't want to take any chances on harming the car.

By the way, once I got the car on a nice long hill the ICE turned itself off and the battery recharged itself. It recovered about half the gage by the time we drove the two miles or so.

Coming up on six months ownership and I am still impressed!

 

You can't hurt the car...unless you forget to change the oil.
If you're sitting with the car powered on, and the battery got low, the engine would have turned on to recharge the battery.
((I am not sure what would happen if the AC was on, but car wasn't powered on with the READY light illuminated, however))

 

Amen. That is my piggest pet peeve with the ergonomics of the car...that and the 1980s cyan backlights...

In plain terms, the engine will run while idling in hot or cold temperatures if you don't have ECON on. When parking outside in the bitter Chicago winter last year my engine would never stop running without econ on for short trips (5-10 minutes). Without ECON I was getting around 27. Even with ECON I was getting 32 average down from 38 in the summer. The most annoying thing is you need defrost in the winter, so by turning on defrost it turns off econ (understandable since it needs the A/C and heat to produce hot dry air), but it is annoying that it doesn't restore your previous setting once you return to AUTO. Just because it has to override ECON for defrost doesn't mean it should turn it off after defrost is off. Who engineered that?

Also, it would be nice to have econ turn off the engine entirely while idling in cold temperatures. Instead, it still runs the engine for the frist few minutes to warm it up regardless of ECON. The only way to override this is to turn the heat OFF at stoplights, then back on....very annoying.