Well, my limit for keeping the car powered is 5 min. I find that once the car has been sitting idle for a while, it will be running rich for the first minute anyway. It's a little worst than a full warm start but not by much, especially when the outside temperature is warm.

And I have a Canadian package A, i.e. no smart entry. When the car is powered up, the key fob is locked into the slot. I have to take the physical key out of the fob and lock the door from outside. I normally turn off my MFD when I get out that way, but the Canadian cars have daytime running lights which is a big giveaway. I just don't feel confortable leaving the car like that for too long.

But then again I'm not shooting for 900 mile tank...

Andy