Can anyone verify how much of a hit to their FE occurs when they do this?

Jess

 

this is very interesting. I will try it when I warm up my car outside today. Sub 0 temps here in chicago. I would guess it might waste a little more gas by doing this..but it might not matter much because its already running the engine in park anyways.

 

That was my thought exactly. FE is out the window when you're sitting there shivering, waiting for the heat to come (and for your kid to come out of the school). You might as well put some charge into the system while you wait. And the extra load might help the engine warm up a tiny bit faster too.

 

Maybe I spoke too soon, since it has not been possible to repeat this behaviour since. Hmmmm.