Gas is most definitly less expensive to heat with than oil. Oil is expensive. Switch to the gas.

Swithcing from oil to gas, especially when the gas line is already in the house, is an very easy decision. You will easily cut your heating bills in half.

I recommend you have the plumber install a separate gas hot water. The hot water heater can be sized to your needs. Usually 40-50 gallons is adequate for most families. This is also a more efficient to heat hot water resulting in additional savings.

We switched to a gas fired steam system in 2009 and never looked back. We're saving about $1200 yearly on heating.