My furnace runs off of fuel oil &/or Kerosene. I can even mix the 2 together.
Fuel oil gums up below 30F so I usually just have Kerosene, it's a little more expensive but it's cheaper than replacing my furnace when the oil gums up & ruins it.
It's not that bad either, it costs me about $400-500 to heat all year long, even last year when we had a LOT of below zero days.