The reason I travel to warmer weather in the winter is that I dislike cold weather. So living in and out of my Prius Campervan has its challenges and cold weather is one of them as I don't have a little buddy heater as I feel it is too dangerous in such a small space. Last year my coldest over night was 19 degrees in Bryce Canyon National Park. I slept in my -20 degree sleeping bag with head under the covers with a tunnel for my nose to get fresh air that wasn't too cold. Yes I wore a fleece hat.
I was going to do the same thing last night (Night 1) but I was asked by one of my Campervan friends why don't I just leave the Prius on all night and it will run as needed.
This reminded me of another Person who wrote me about using the Prius for heat overnight and this would be an excellent test with such low temperatures (14 degrees) and wind.
The results were positive:
(Temperature was set for 65 in the Prius and 14 outside)
- with the car already warm the Prius would run about one minute for every 5 with the engine not running. I didn't actually time it so these are estimates.
- the privacy curtain was across the back of the front seats so there was no direct airflow to the back but that's ok as I wished it cooler in the back since I have such a warm sleeping bag.
- the Prius is drafty do if the car was designed specifically for heating and cooling with insulation the engine would run less. The Prius may be drafty as it has the high voltage battery cooler and static vent in the back near 12 volt battery.
- initially I woke from the engine starting every 5 minutes but soon went to sleep and woke 5 hours later.
In any case I went to bed with an average of 46.5 mpg (Note: when running the heat in the passenger compartment while driving especially at such lie temperatures mpg goes down.) I woke up with 35.4 mpg. I didn't calculate fuel usage for my 5 hours of running the Prius that way, but I had only gotten fuel 120 miles before I stopped.
The experiment worked great and I was toasty all night. Yet another plus for the Prius as a Campervan.
I do have a smoke/CO detector on the ceiling of my Orius Campervan for my safety.