electric oil heater?

Question

are oil filled electric heaters cheaper to run than a gas furnances

Answer 1

It's very rare that an electric appliance will heat cheaper than any type of combusted fuel.

The oil filled radiators are typically employed to take the chill off a room that is either poorly insulated or perhaps in a converted basement (surrounded by cold concrete and block). The oil just holds the heat after the elements get turned off, so you continue to feel the warmth. It adds nothing to the efficiency, but certainly augments the comfort factor.

You could conceivably lower you household temperature (gas furnace) and make the room you are in warmer with the electric heater.

Depending on how your house is laid out, failing to run your household heater (altogether) may permit your water pipes to freeze - eliminating any savings if the pipes burst.