Let's say it is 20 degrees Fahrenheit outside. If I have my thermostat set at 60 F, then each time my house dips below that temperature, my furnace should kick on and reheat it to 60 F. And the cycle continues... If I have my thermostat set at 68 F, then the scenario remains the same, it's just that the furnace kicks on below 68. Does the furnace burn more heating oil to keep the house at 68 than it does at 60? Does a house at 68 F lose heat to the 20 F surroundings at a greater rate than does the house set at 60 F? If not, is there any savings...that is, after the house initially reaches the set temperature?