Camping well below freezing - Sweden over winter

this reminds me of what my father claimed when he was young in Northern Minnesota. he said that they would drain out the oil to keep it semi fluid for starting the next morning. don't know if it was factual or not but I do remember visiting my uncles/cousins when I had a convertible and they insisted that I put down the top on a day that I would consider to be raw and certainly not convertible weather.
bumpy