In California the temperature is often low in the morning (upper 60's) but with the sun and the windows closed the car can heat up quickly. Is it better for the gas mileage to turn the air conditioner temperature to match the temperature of the outside? Or should we just leave the temperature at 78 degrees?
In the morning, I put it on vent, fresh air mode with the AC off, but that is while it's still dark. I would say do whatever is required to stay comfortable, The AC does dehumidify if you need that. I believe the traction battery doesn't like heat, so I keep the car cool in the hope that it is helping to cool the battery. Yes there will be some MPG hit from running the AC, size of the hit is based on how hard it works of course, from what you describe, I would think the loss would be minimal.
I would try turning down the temp to LO and using VENT to see if that makes you comfortable enough. If so, then you found the match. If I recall from when living out in CA for 11 years, the mornings could be cool, and with the tpical low humidity you should not need the A/C. By the time you leave work I would think sure, it's safe to go an use it. The draw on this A/C unit is not as severe to some other non-hybrid vehicles. And in using the ECO MODE should help to keep your percentage of loss of MPG to a minimum.
